diff --git a/UnitTestProject/Modules/SwapModule/ReturnLegs/MtmCalcTest.cs b/UnitTestProject/Modules/SwapModule/ReturnLegs/MtmCalcTest.cs
index d5ee1d62..da6969dd 100644
--- a/UnitTestProject/Modules/SwapModule/ReturnLegs/MtmCalcTest.cs
+++ b/UnitTestProject/Modules/SwapModule/ReturnLegs/MtmCalcTest.cs
@@ -9,14 +9,12 @@ namespace UnitTestProject.Modules.SwapModule.ReturnLegs
         [TestMethod]
         public void MarketValue_多头_为正()
         {
-            // 标的价100 × 1000张 × 乘数1 × 多头(+1) = 100000
             Assert.AreEqual(100_000m, MtmCalc.MarketValue(100m, 1000m, 1m, 1));
         }
 
         [TestMethod]
         public void MarketValue_空头_为负()
         {
-            // 空头 shortRatio=-1
             Assert.AreEqual(-100_000m, MtmCalc.MarketValue(100m, 1000m, 1m, -1));
         }
 
@@ -29,22 +27,19 @@ namespace UnitTestProject.Modules.SwapModule.ReturnLegs
         [TestMethod]
         public void UnrealizedPnl_多头浮盈()
         {
-            // (105-100) × 1000 × 1 × 1 × 1 = 5000
-            Assert.AreEqual(5000m, MtmCalc.UnrealizedPnl(105m, 100m, 1000m, 1m, 1, 1m));
+            Assert.AreEqual(5000m, MtmCalc.UnrealizedPnl(105m, 100m, 1000m, 1m, 1, 1));
         }
 
         [TestMethod]
         public void UnrealizedPnl_多头浮亏()
         {
-            // (95-100) × 1000 × 1 × 1 × 1 = -5000
-            Assert.AreEqual(-5000m, MtmCalc.UnrealizedPnl(95m, 100m, 1000m, 1m, 1, 1m));
+            Assert.AreEqual(-5000m, MtmCalc.UnrealizedPnl(95m, 100m, 1000m, 1m, 1, 1));
         }
 
         [TestMethod]
         public void UnrealizedPnl_空头反向()
         {
-            // 空头: 价格跌=盈利 (95-100) × 1000 × 1 × (-1) × 1 = 5000
-            Assert.AreEqual(5000m, MtmCalc.UnrealizedPnl(95m, 100m, 1000m, 1m, -1, 1m));
+            Assert.AreEqual(5000m, MtmCalc.UnrealizedPnl(95m, 100m, 1000m, 1m, -1, 1));
         }
     }
 }
diff --git a/YLErpDAL/Modules/SwapModule/SwapEodPositionService.cs b/YLErpDAL/Modules/SwapModule/SwapEodPositionService.cs
index 408e23e4..c9da80f1 100644
--- a/YLErpDAL/Modules/SwapModule/SwapEodPositionService.cs
+++ b/YLErpDAL/Modules/SwapModule/SwapEodPositionService.cs
@@ -1800,8 +1800,7 @@ namespace YLErp.Modules.SwapModule
             if (valueDate > td.StartDate.Value && curretEod.PosiQuantity > 0)
             {
                 decimal payment = CalcBondPayment(curretEod.UnderlyingCode, eod.ValueDate, valueDate, curretEod.PosiQuantity, shortRatio, directionRatio);
-                // 考虑增值税
-                curretEod.TdPosiDividend = Math.Round(payment / (1 + tax) * (1 - tax), 2);
+                curretEod.TdPosiDividend = DividendCalc.AfterTax(payment, tax);
             }
             curretEod.PosiDividendSum = eod.PosiQuantity > 0 ? Math.Round(eod.PosiDividendSum + curretEod.TdPosiDividend, 2) : 0;
             curretEod.PosiQuantity = eod.PosiQuantity;
@@ -1891,7 +1890,7 @@ namespace YLErp.Modules.SwapModule
             var originNotional = (decimal)td.OriginalStockEqvNotional / swapPosition.PosiNetPrice;
             decimal totalPayment = CalcBondPayment(curretEod.UnderlyingCode, td.StartDate.Value, valueDate, (decimal)originNotional, shortRatio, directionRatio);
             decimal tax = um.ValueAddedTax ?? 0;
-            decimal totalInterest = totalPayment / (1 + tax) * (1 - tax);
+            decimal totalInterest = DividendCalc.AfterTaxRaw(totalPayment, tax);
             SetPriceInfoByFlowEvent(eod, curretEod, unwindEvents, swapPosition);
             curretEod.dv01 = Dv01Helper.CalcDv01(eod.UnderlyingCode, curretEod.PosiQuantity, eod.PosiDirection, eod.PositionType, vobp);
             curretEod.UnderlyingPrice = price;
@@ -1903,7 +1902,7 @@ namespace YLErp.Modules.SwapModule
             if (valueDate > td.StartDate.Value && (curretEod.PosiQuantity > 0))
             {
                 decimal payment = CalcBondPayment(curretEod.UnderlyingCode, eod.ValueDate, valueDate, curretEod.PosiQuantity, shortRatio, directionRatio);
-                curretEod.TdPosiDividend = Math.Round(payment / (1 + tax) * (1 - tax), 2);
+                curretEod.TdPosiDividend = DividendCalc.AfterTax(payment, tax);
             }
             curretEod.RealizedMtmPnL = eod.RealizedMtmPnL + curretEod.TdCloseMtmPnl;
             // 当日浮动端平仓盈亏·分红（仅来自平仓事件 和 互换 中已实现的分红）
@@ -2092,7 +2091,7 @@ namespace YLErp.Modules.SwapModule
             {
                 decimal tax = um.ValueAddedTax ?? 0;
                 decimal payment = CalcBondPayment(curretEod.UnderlyingCode, td.StartDate.Value, settleDate, curretEod.PosiQuantity, shortRatio, directionRatio);
-                payment = Math.Round(payment / (1 + tax) * (1 - tax), 2);
+                payment = DividendCalc.AfterTax(payment, tax);
                 //var consumedDividend = CalcConsumedDividend(curretEod, unwindEvents); 首日应该没有分红
                 curretEod.TdPosiDividend = payment;
                 curretEod.PosiDividendSum = payment;