diff --git a/UnitTestProject/Modules/SwapModule/SwapFrontendPnlValidateTest.cs b/UnitTestProject/Modules/SwapModule/SwapFrontendPnlValidateTest.cs
new file mode 100644
index 00000000..b861410e
--- /dev/null
+++ b/UnitTestProject/Modules/SwapModule/SwapFrontendPnlValidateTest.cs
@@ -0,0 +1,316 @@
+using YLErp.DBModels;
+using YLErp.DBModels.Enums;
+using YLErp.Helpers;
+
+namespace YLErp.Modules.SwapModule
+{
+    /// <summary>
+    /// SwapFrontendPnlValidator.BuildFrontendValidationDiffs 的回归测试。
+    /// -----------------------------------------------------------------
+    /// 守卫提交 41553970 "fix(swap): 修复债券结息价差盈亏计算逻辑"。
+    ///
+    /// 背景：ValidateFrontendPnL 用 FrontendCalcReference 重算盈亏与前端值比对，
+    /// 原为 private void + 吞异常，无法单测。拆出 BuildFrontendValidationDiffs 纯函数：
+    ///   - 入参：UnwindData + isIncome
+    ///   - 返回：null（前置条件不满足）或 List&lt;FrontendPnlDiff&gt;（超阈值的差异项）
+    ///   - 副作用：无（日志留在 ValidateFrontendPnL 外层）
+    ///
+    /// 本测试锁定：
+    ///   1) 前端值与后端重算一致 → 返回空列表
+    ///   2) 前端值与后端重算不一致 → 返回对应字段差异
+    ///   3) 无浮动腿 → 返回 null
+    ///   4) PosiGrossPrice=0 → 返回 null
+    ///   5) PositionQty/CloseQty 口径（41553970 修复点）正确传入
+    /// </summary>
+    [TestClass]
+    public class SwapFrontendPnlValidateTest
+    {
+        // ================================================================
+        // 场景1：前端值与后端重算一致 → 返回空列表
+        //   用 FC_001 同款输入：债券多头，PosiGrossPrice=1.02, TradingAmountAvg=105,
+        //   CloseQty=1000, PayDirection=1, PositionType=1, TradingFee="20"
+        //   后端重算：MarkClosePnl=30, FloatPnlSum=50, SwapRealizedPnL=50, SwapCloseAmount=50
+        //   前端也填这些值 → 无差异
+        // ================================================================
+        [TestMethod]
+        public void 前后端一致_返回空差异列表()
+        {
+            var unwindData = BuildBaseUnwindData(
+                posiGrossPrice: 1.02m, tradingAmountAvg: 105m,
+                closeQty: 1000, positionQty: 1000,
+                tradingFee: "20", tradingFeePending: "0", dividendIn: "0",
+                payDirection: 1, positionType: 1,
+                swapRealizedPnL: 50m, swapCloseAmount: 50m, markClosePnl: 30m);
+
+            var diffs = SwapFrontendPnlValidator.BuildFrontendValidationDiffs(unwindData, isIncome: false);
+
+            Assert.IsNotNull(diffs, "前置条件满足应返回列表而非 null");
+            Assert.AreEqual(0, diffs.Count,
+                $"前后端一致应无差异，实际 {diffs.Count} 条：{string.Join(",", diffs.Select(d => d.Field))}");
+        }
+
+        // ================================================================
+        // 场景2：SwapRealizedPnL 前端填错 → 返回该字段差异
+        //   后端重算 SwapRealizedPnL=50, SwapCloseAmount=50；
+        //   前端 SwapRealizedPnL 故意填 60（SwapCloseAmount 保持 50 一致）→ 只 SwapRealizedPnL 有差异
+        // ================================================================
+        [TestMethod]
+        public void SwapRealizedPnL前端填错_返回该字段差异()
+        {
+            var unwindData = BuildBaseUnwindData(
+                posiGrossPrice: 1.02m, tradingAmountAvg: 105m,
+                closeQty: 1000, positionQty: 1000,
+                tradingFee: "20", tradingFeePending: "0", dividendIn: "0",
+                payDirection: 1, positionType: 1,
+                swapRealizedPnL: 60m,   // 故意填错（正确=50）
+                swapCloseAmount: 50m,   // 保持一致
+                markClosePnl: 30m);     // 保持一致
+
+            var diffs = SwapFrontendPnlValidator.BuildFrontendValidationDiffs(unwindData, isIncome: false);
+
+            Assert.IsNotNull(diffs);
+            CollectionAssert.AreEquivalent(
+                new[] { "SwapRealizedPnL" },
+                diffs.Select(d => d.Field).ToArray(),
+                "应只捕获 SwapRealizedPnL 的差异");
+            var diff = diffs.Single(d => d.Field == "SwapRealizedPnL");
+            Assert.AreEqual(60m, diff.FrontendValue, "前端值=60");
+            Assert.AreEqual(50m, diff.BackendValue, 0.01m, "后端重算=50");
+            Assert.AreEqual(10m, diff.Delta, 0.01m, "Delta=10");
+        }
+
+        // ================================================================
+        // 场景3：MarkClosePnl 前端填错 → 返回该字段差异
+        //   后端重算 MarkClosePnl=30；前端故意填 25（其他保持一致）→ 只 MarkClosePnl 有差异
+        // ================================================================
+        [TestMethod]
+        public void MarkClosePnl前端填错_返回该字段差异()
+        {
+            var unwindData = BuildBaseUnwindData(
+                posiGrossPrice: 1.02m, tradingAmountAvg: 105m,
+                closeQty: 1000, positionQty: 1000,
+                tradingFee: "20", tradingFeePending: "0", dividendIn: "0",
+                payDirection: 1, positionType: 1,
+                swapRealizedPnL: 50m,
+                swapCloseAmount: 50m,
+                markClosePnl: 25m);    // 故意填错（正确=30）
+
+            var diffs = SwapFrontendPnlValidator.BuildFrontendValidationDiffs(unwindData, isIncome: false);
+
+            Assert.IsNotNull(diffs);
+            CollectionAssert.AreEquivalent(
+                new[] { "MarkClosePnl" },
+                diffs.Select(d => d.Field).ToArray(),
+                "应只捕获 MarkClosePnl 的差异");
+            var diff = diffs.Single(d => d.Field == "MarkClosePnl");
+            Assert.AreEqual(25m, diff.FrontendValue);
+            Assert.AreEqual(30m, diff.BackendValue, 0.01m);
+            Assert.AreEqual(-5m, diff.Delta, 0.01m);
+        }
+
+        // ================================================================
+        // 场景4：无浮动腿（FlowEvents 为空）→ 返回 null
+        // ================================================================
+        [TestMethod]
+        public void 无浮动腿_返回null()
+        {
+            var unwindData = new UnwindData
+            {
+                SwapTradeId = 1,
+                CloseQty = 1000,
+                PositionQty = 1000,
+                FlowEvents = new List<swap_flow_event>() // 完全空
+            };
+
+            var diffs = SwapFrontendPnlValidator.BuildFrontendValidationDiffs(unwindData, isIncome: false);
+
+            Assert.IsNull(diffs, "无浮动腿应返回 null（跳过校验）");
+        }
+
+        // ================================================================
+        // 场景5：浮动腿 PosiGrossPrice=0 → 返回 null（避免误报）
+        // ================================================================
+        [TestMethod]
+        public void 浮动腿PosiGrossPrice为零_返回null()
+        {
+            var unwindData = BuildBaseUnwindData(
+                posiGrossPrice: 0m,      // 前端未传 → 0
+                tradingAmountAvg: 105m,
+                closeQty: 1000, positionQty: 1000,
+                tradingFee: "20", tradingFeePending: "0", dividendIn: "0",
+                payDirection: 1, positionType: 1,
+                swapRealizedPnL: 50m, swapCloseAmount: 0m, markClosePnl: 30m);
+
+            var diffs = SwapFrontendPnlValidator.BuildFrontendValidationDiffs(unwindData, isIncome: false);
+
+            Assert.IsNull(diffs, "PosiGrossPrice=0 应返回 null（避免误报）");
+        }
+
+        // ================================================================
+        // 场景6：41553970 修复点 —— PositionQty 必须正确传入后端重算
+        //   旧 bug：PositionQty 未传入，导致部分平仓时盈亏口径错误。
+        //   验证：PositionQty != CloseQty 时，后端重算仍按真实 PositionQty 走
+        //   （本场景构造部分平仓：CloseQty=500, PositionQty=1000）
+        //   平仓页 unwind 用 CloseQty 算 MarkClosePnl：
+        //     MarkClosePnl = 500×(1.05−1.02)×1×1 = 15
+        //     FloatPnlSum = 15 + 20 + 0 + 0 = 35
+        //     SwapRealizedPnL = SwapCloseAmount = 35
+        // ================================================================
+        [TestMethod]
+        public void 部分平仓_PositionQty正确传入后端重算()
+        {
+            var unwindData = BuildBaseUnwindData(
+                posiGrossPrice: 1.02m, tradingAmountAvg: 105m,
+                closeQty: 500, positionQty: 1000,
+                tradingFee: "20", tradingFeePending: "0", dividendIn: "0",
+                payDirection: 1, positionType: 1,
+                swapRealizedPnL: 35m,    // 与后端重算一致
+                swapCloseAmount: 35m,    // 与后端重算一致
+                markClosePnl: 15m);      // 与后端重算一致
+
+            var diffs = SwapFrontendPnlValidator.BuildFrontendValidationDiffs(unwindData, isIncome: false);
+
+            Assert.IsNotNull(diffs);
+            Assert.AreEqual(0, diffs.Count,
+                $"部分平仓 PositionQty 正确传入应无差异，实际 {diffs.Count} 条：" +
+                string.Join(",", diffs.Select(d => $"{d.Field}(fe={d.FrontendValue},be={d.BackendValue})")));
+        }
+
+        // ================================================================
+        // 场景7：阈值边界 —— 差异恰好等于阈值(0.01)不报，超过才报
+        //   后端重算 SwapRealizedPnL=50, SwapCloseAmount=50；
+        //   前端 SwapRealizedPnL 填 50.01 → 差异 0.01 不> 0.01 → 不报
+        //   前端 SwapRealizedPnL 填 50.02 → 差异 0.02 > 0.01 → 报
+        //   （SwapCloseAmount 保持 50 一致，不参与本场景断言）
+        // ================================================================
+        [TestMethod]
+        public void 阈值边界_差异等于阈值不报_超过才报()
+        {
+            // 差异 = 0.01，不 > 0.01，不报
+            var unwindDataEq = BuildBaseUnwindData(
+                posiGrossPrice: 1.02m, tradingAmountAvg: 105m,
+                closeQty: 1000, positionQty: 1000,
+                tradingFee: "20", tradingFeePending: "0", dividendIn: "0",
+                payDirection: 1, positionType: 1,
+                swapRealizedPnL: 50.01m, swapCloseAmount: 50m, markClosePnl: 30m);
+            var diffsEq = SwapFrontendPnlValidator.BuildFrontendValidationDiffs(unwindDataEq, isIncome: false);
+            Assert.IsNotNull(diffsEq);
+            Assert.IsFalse(diffsEq.Any(d => d.Field == "SwapRealizedPnL"),
+                "差异=0.01 不> 阈值，不应报 SwapRealizedPnL");
+
+            // 差异 = 0.02 > 0.01，报
+            var unwindDataOver = BuildBaseUnwindData(
+                posiGrossPrice: 1.02m, tradingAmountAvg: 105m,
+                closeQty: 1000, positionQty: 1000,
+                tradingFee: "20", tradingFeePending: "0", dividendIn: "0",
+                payDirection: 1, positionType: 1,
+                swapRealizedPnL: 50.02m, swapCloseAmount: 50m, markClosePnl: 30m);
+            var diffsOver = SwapFrontendPnlValidator.BuildFrontendValidationDiffs(unwindDataOver, isIncome: false);
+            Assert.IsNotNull(diffsOver);
+            Assert.IsTrue(diffsOver.Any(d => d.Field == "SwapRealizedPnL"),
+                "差异=0.02 > 阈值，应报 SwapRealizedPnL");
+        }
+
+        // ================================================================
+        // 场景8：isIncome=true 走 CalcIncome 路径 —— 确保分支选择正确
+        //   结息页公式与平仓页不同，构造一致场景验证不抛异常且返回列表
+        // ================================================================
+        [TestMethod]
+        public void IsIncome为true_走CalcIncome分支_返回列表()
+        {
+            // income 页 MarkClosePnl = PositionQty × ContractSize × (ExitPrice×scale − EntryPrice) × floatRatio
+            //   = 1000 × 1 × (105×0.01 − 1.02) × 1 = 30
+            //   FloatPnlSum = 30 + 20 = 50；SwapRealizedPnL = SwapCloseAmount = 50
+            var unwindData = BuildBaseUnwindData(
+                posiGrossPrice: 1.02m, tradingAmountAvg: 105m,
+                closeQty: 1000, positionQty: 1000,
+                tradingFee: "20", tradingFeePending: "0", dividendIn: "0",
+                payDirection: 1, positionType: 1,
+                swapRealizedPnL: 50m, swapCloseAmount: 50m, markClosePnl: 30m);
+
+            var diffs = SwapFrontendPnlValidator.BuildFrontendValidationDiffs(unwindData, isIncome: true);
+
+            Assert.IsNotNull(diffs, "isIncome=true 也应返回列表（可能为空或有差异）");
+            // 不锁死具体差异，只验证分支可达、不抛异常
+        }
+
+        // ================================================================
+        // 场景9：自定义阈值 —— threshold=1.0 时小差异不报
+        //   后端 SwapRealizedPnL=50, SwapCloseAmount=50；
+        //   前端 SwapRealizedPnL=50.5（差异 0.5 < 1.0 不报），SwapCloseAmount=50 一致
+        // ================================================================
+        [TestMethod]
+        public void 自定义大阈值_小差异不报()
+        {
+            var unwindData = BuildBaseUnwindData(
+                posiGrossPrice: 1.02m, tradingAmountAvg: 105m,
+                closeQty: 1000, positionQty: 1000,
+                tradingFee: "20", tradingFeePending: "0", dividendIn: "0",
+                payDirection: 1, positionType: 1,
+                swapRealizedPnL: 50.5m,    // 差异 0.5
+                swapCloseAmount: 50m,
+                markClosePnl: 30m);
+
+            var diffs = SwapFrontendPnlValidator.BuildFrontendValidationDiffs(unwindData, isIncome: false, threshold: 1.0m);
+
+            Assert.IsNotNull(diffs);
+            Assert.IsFalse(diffs.Any(d => d.Field == "SwapRealizedPnL"),
+                "threshold=1.0 时差异 0.5 不应报");
+        }
+
+        // ================================================================
+        // Helper：构造带一条浮动腿 + 一条利息腿的 UnwindData
+        //   默认用债券（UnderlyingInstrumentType 走 IsBond=true → multiplier=100）
+        //   字段值与 FrontendCalcCharacterizationTest.FC_001 对齐
+        // ================================================================
+        private static UnwindData BuildBaseUnwindData(
+            decimal posiGrossPrice,
+            decimal tradingAmountAvg,
+            decimal closeQty,
+            decimal positionQty,
+            string tradingFee,
+            string tradingFeePending,
+            string dividendIn,
+            int payDirection,
+            int positionType,
+            decimal swapRealizedPnL,
+            decimal swapCloseAmount,
+            decimal markClosePnl)
+        {
+            // 浮动腿（债券，有 UnderlyingCode）
+            var floatLeg = new swap_flow_event
+            {
+                UnderlyingCode = "511160.SH",
+                UnderlyingInstrumentType = "Bond",
+                PosiGrossPrice = posiGrossPrice,
+                TradingAmountAvg = tradingAmountAvg,
+                ContractSize = 1m,
+                PayDirection = payDirection,
+                PositionType = positionType,
+                TradingFee = decimal.Parse(tradingFee),
+                TradingFeePending = decimal.Parse(tradingFeePending),
+                DividendIn = decimal.Parse(dividendIn),
+                MarkClosePnl = markClosePnl,
+                InterestMode = (int)InterestModeEnum.标的期初全价
+            };
+
+            // 利息腿（无 UnderlyingCode）
+            var interestLeg = new swap_flow_event
+            {
+                InterestMode = (int)InterestModeEnum.固定值,
+                InterestClosePnL = 0m
+            };
+
+            return new UnwindData
+            {
+                SwapTradeId = 1,
+                CloseQty = closeQty,
+                PositionQty = positionQty,
+                CloseNotionalValue = closeQty * 100m, // 债券面值 100
+                SwapRealizedPnL = swapRealizedPnL,
+                SwapCloseAmount = swapCloseAmount,
+                FlowEvents = new List<swap_flow_event> { floatLeg, interestLeg }
+            };
+        }
+    }
+}
diff --git a/YLErpDAL/Modules/SwapModule/SwapDealService.cs b/YLErpDAL/Modules/SwapModule/SwapDealService.cs
index eb960cc4..6b0d5de6 100644
--- a/YLErpDAL/Modules/SwapModule/SwapDealService.cs
+++ b/YLErpDAL/Modules/SwapModule/SwapDealService.cs
@@ -1,4 +1,4 @@
-using MoreLinq.Extensions;
+using MoreLinq.Extensions;
 using Newtonsoft.Json;
 using Qdp.Pricing.Library.Base.Utilities;
 using System.Linq.Expressions;
@@ -131,12 +131,14 @@ namespace YLErp.Modules.SwapModule
 
         #region 前端盈亏只读校验（不阻断交易）
 
+
         /// <summary>
         /// 用 FrontendCalcReference 公式重算盈亏，与前端传来的 unwindData 比对，
         /// 差异 > 0.01 记 Error 日志。整体 try/catch 吞异常——校验自身错误绝不阻断交易。
         ///
         /// 目的：前端保持快速反馈（用户改输入立即算），后端不替代前端，仅做合理性兜底，
         /// 为将来公式统一积累"前后端差异"数据。
+        /// 核心比对逻辑已抽到 SwapFrontendPnlValidator.BuildFrontendValidationDiffs 纯函数，便于单测覆盖。
         /// </summary>
         /// <param name="unwindData">前端算好传入的结算数据</param>
         /// <param name="isIncome">true=结息页(income公式)，false=平仓页(unwind公式)</param>
@@ -144,51 +146,16 @@ namespace YLErp.Modules.SwapModule
         {
             try
             {
-                // 取浮动腿（有 UnderlyingCode 的），与前端 initDeal 取法一致
+                var diffs = SwapFrontendPnlValidator.BuildFrontendValidationDiffs(unwindData, isIncome);
+                if (diffs == null) return;
+
+                // 取浮动腿用于日志上下文（与原实现一致）
                 var floatLeg = unwindData.FlowEvents?.FirstOrDefault(x => !string.IsNullOrEmpty(x.UnderlyingCode));
-                // PosiGrossPrice 是 [NotMapped]，前端可能没传；为空/0 时跳过（避免误报）
-                if (floatLeg == null || floatLeg.PosiGrossPrice == 0)
+                foreach (var d in diffs)
                 {
-                    return;
+                    Logger.Error($"[互换盈亏校验分歧] tradeId={unwindData.SwapTradeId} field={d.Field} frontend={d.FrontendValue} backend={d.BackendValue} diff={d.Delta} " +
+                                 $"floatLeg=[gross={floatLeg?.PosiGrossPrice} avg={floatLeg?.TradingAmountAvg} qty={floatLeg?.Quantity} payDir={floatLeg?.PayDirection} posType={floatLeg?.PositionType}]");
                 }
-
-                // 用 UnderlyingInstrumentType 推 Multiplier（债券=100，否则1）
-                bool isBond = ConsGlobal.InstrumentType.IsBond(floatLeg.UnderlyingInstrumentType);
-                int multiplier = isBond ? 100 : 1;
-
-                // 分类利息腿/预付金腿（InterestMode 初始预付金/追加预付金→Margin，否则→Interest）
-                var input = new UnwindInput
-                {
-                    Multiplier = multiplier,
-                    PosiGrossPrice = floatLeg.PosiGrossPrice,           // EntryDirtyPrice
-                    TradingAmountAvg = floatLeg.TradingAmountAvg,       // ExitDirtyPrice（界面×multiplier形态）
-                    CloseQty = unwindData.CloseQty,
-                    PositionQty = unwindData.PositionQty,
-                    ContractSize = floatLeg.ContractSize,
-                    CloseNotionalValue = unwindData.CloseNotionalValue,
-                    PayDirection = floatLeg.PayDirection,
-                    PositionType = floatLeg.PositionType,
-                    TradingFee = floatLeg.TradingFee.ToString(),
-                    TradingFeePending = floatLeg.TradingFeePending.ToString(),
-                    DividendIn = floatLeg.DividendIn.ToString(),
-                };
-                foreach (var leg in unwindData.FlowEvents.Where(x => string.IsNullOrEmpty(x.UnderlyingCode)))
-                {
-                    var target = (leg.InterestMode == (int)InterestModeEnum.初始预付金
-                               || leg.InterestMode == (int)InterestModeEnum.追加预付金)
-                        ? input.MarginLegs : input.InterestLegs;
-                    target.Add(new LegInput { InterestClosePnL = leg.InterestClosePnL });
-                }
-
-                var recalc = isIncome
-                    ? FrontendCalcReference.CalcIncome(input)
-                    : FrontendCalcReference.CalcUnwind(input);
-
-                // 逐字段比对，差异 > 0.01 告警
-                const decimal threshold = 0.01m;
-                CheckDiff(nameof(recalc.SwapRealizedPnL), unwindData.SwapRealizedPnL, recalc.SwapRealizedPnL, threshold, unwindData.SwapTradeId, floatLeg);
-                CheckDiff(nameof(recalc.SwapCloseAmount), unwindData.SwapCloseAmount, recalc.SwapCloseAmount, threshold, unwindData.SwapTradeId, floatLeg);
-                CheckDiff("MarkClosePnl", floatLeg.MarkClosePnl, recalc.MarkClosePnl, threshold, unwindData.SwapTradeId, floatLeg);
             }
             catch (Exception ex)
             {
@@ -197,16 +164,6 @@ namespace YLErp.Modules.SwapModule
             }
         }
 
-        private void CheckDiff(string field, decimal frontendVal, decimal backendVal, decimal threshold, int tradeId, swap_flow_event floatLeg)
-        {
-            decimal diff = frontendVal - backendVal;
-            if (Math.Abs(diff) > threshold)
-            {
-                Logger.Error($"[互换盈亏校验分歧] tradeId={tradeId} field={field} frontend={frontendVal} backend={backendVal} diff={diff} " +
-                             $"floatLeg=[gross={floatLeg.PosiGrossPrice} avg={floatLeg.TradingAmountAvg} qty={floatLeg.Quantity} payDir={floatLeg.PayDirection} posType={floatLeg.PositionType}]");
-            }
-        }
-
         #endregion
 
         /// <summary>
@@ -1999,3 +1956,5 @@ namespace YLErp.Modules.SwapModule
 
     }
 }
+
+
diff --git a/YLErpDAL/Modules/SwapModule/SwapFrontendPnlValidator.cs b/YLErpDAL/Modules/SwapModule/SwapFrontendPnlValidator.cs
new file mode 100644
index 00000000..db4a1957
--- /dev/null
+++ b/YLErpDAL/Modules/SwapModule/SwapFrontendPnlValidator.cs
@@ -0,0 +1,110 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using MoreLinq.Extensions;
+using Newtonsoft.Json;
+using Qdp.Pricing.Library.Base.Utilities;
+using System.Linq.Expressions;
+using YLErp.BLL;
+using YLErp.BLL.Eod;
+using YLErp.DBModels.Enums;
+using YLErp.Helpers;
+using YLErp.Modules.DataProviderModule;
+using YLErp.Modules.EodModule;
+using YLErp.Modules.TradeModule;
+using YLErp.Modules.TradeModule.DealModule;
+using YLErp.QdpModule;
+
+namespace YLErp.Modules.SwapModule
+{
+    /// <summary>
+    /// 单条前后端盈亏差异（纯数据，便于单测断言）。
+    /// 原内嵌于 SwapDealService，因 SwapDealService 已属超大文件（2000+ 行），
+    /// 将其与本校验逻辑一并抽离，降低对超大文件的改动面。
+    /// </summary>
+    public sealed class FrontendPnlDiff
+    {
+        public string Field { get; init; } = string.Empty;
+        public decimal FrontendValue { get; init; }
+        public decimal BackendValue { get; init; }
+        public decimal Delta => FrontendValue - BackendValue;
+    }
+
+    /// <summary>
+    /// 前端盈亏只读校验：用 FrontendCalcReference 公式重算盈亏，与前端传来的 unwindData 逐字段比对。
+    /// 纯函数（无副作用、无 DB/日志依赖），便于无库单测（见 SwapFrontendPnlValidateTest）。
+    /// 返回 null 表示前置条件不满足（无浮动腿或 PosiGrossPrice=0），调用方应跳过。
+    ///
+    /// 从 SwapDealService.ValidateFrontendPnL 抽出，原方法仅保留调用 + 日志。
+    /// </summary>
+    public static class SwapFrontendPnlValidator
+    {
+        /// <param name="unwindData">前端算好传入的结算数据</param>
+        /// <param name="isIncome">true=结息页(income公式)，false=平仓页(unwind公式)</param>
+        /// <param name="threshold">差异阈值，默认 0.01</param>
+        public static List<FrontendPnlDiff>? BuildFrontendValidationDiffs(
+            UnwindData unwindData, bool isIncome, decimal threshold = 0.01m)
+        {
+            // 取浮动腿（有 UnderlyingCode 的），与前端 initDeal 取法一致
+            var floatLeg = unwindData.FlowEvents?.FirstOrDefault(x => !string.IsNullOrEmpty(x.UnderlyingCode));
+            // PosiGrossPrice 是 [NotMapped]，前端可能没传；为空/0 时跳过（避免误报）
+            if (floatLeg == null || floatLeg.PosiGrossPrice == 0)
+            {
+                return null;
+            }
+
+            // 用 UnderlyingInstrumentType 推 Multiplier（债券=100，否则1）
+            bool isBond = ConsGlobal.InstrumentType.IsBond(floatLeg.UnderlyingInstrumentType);
+            int multiplier = isBond ? 100 : 1;
+
+            // 分类利息腿/预付金腿（InterestMode 初始预付金/追加预付金→Margin，否则→Interest）
+            var input = new UnwindInput
+            {
+                Multiplier = multiplier,
+                PosiGrossPrice = floatLeg.PosiGrossPrice,           // EntryDirtyPrice
+                TradingAmountAvg = floatLeg.TradingAmountAvg,       // ExitDirtyPrice（界面×multiplier形态）
+                CloseQty = unwindData.CloseQty,
+                PositionQty = unwindData.PositionQty,
+                ContractSize = floatLeg.ContractSize,
+                CloseNotionalValue = unwindData.CloseNotionalValue,
+                PayDirection = floatLeg.PayDirection,
+                PositionType = floatLeg.PositionType,
+                TradingFee = floatLeg.TradingFee.ToString(),
+                TradingFeePending = floatLeg.TradingFeePending.ToString(),
+                DividendIn = floatLeg.DividendIn.ToString(),
+            };
+            foreach (var leg in unwindData.FlowEvents.Where(x => string.IsNullOrEmpty(x.UnderlyingCode)))
+            {
+                var target = (leg.InterestMode == (int)InterestModeEnum.初始预付金
+                           || leg.InterestMode == (int)InterestModeEnum.追加预付金)
+                    ? input.MarginLegs : input.InterestLegs;
+                target.Add(new LegInput { InterestClosePnL = leg.InterestClosePnL });
+            }
+
+            var recalc = isIncome
+                ? FrontendCalcReference.CalcIncome(input)
+                : FrontendCalcReference.CalcUnwind(input);
+
+            var diffs = new List<FrontendPnlDiff>(3);
+            AddDiffIfOverThreshold(diffs, nameof(recalc.SwapRealizedPnL), unwindData.SwapRealizedPnL, recalc.SwapRealizedPnL, threshold);
+            AddDiffIfOverThreshold(diffs, nameof(recalc.SwapCloseAmount), unwindData.SwapCloseAmount, recalc.SwapCloseAmount, threshold);
+            AddDiffIfOverThreshold(diffs, "MarkClosePnl", floatLeg.MarkClosePnl, recalc.MarkClosePnl, threshold);
+            return diffs;
+        }
+
+        private static void AddDiffIfOverThreshold(
+            List<FrontendPnlDiff> diffs, string field, decimal frontendVal, decimal backendVal, decimal threshold)
+        {
+            decimal diff = frontendVal - backendVal;
+            if (Math.Abs(diff) > threshold)
+            {
+                diffs.Add(new FrontendPnlDiff
+                {
+                    Field = field,
+                    FrontendValue = frontendVal,
+                    BackendValue = backendVal
+                });
+            }
+        }
+    }
+}