diff --git a/UnitTestProject/Modules/SwapModule/DealInterestsScenarioTest.cs b/UnitTestProject/Modules/SwapModule/DealInterestsScenarioTest.cs
index ba6f8790..b4b11f31 100644
--- a/UnitTestProject/Modules/SwapModule/DealInterestsScenarioTest.cs
+++ b/UnitTestProject/Modules/SwapModule/DealInterestsScenarioTest.cs
@@ -782,6 +782,31 @@ namespace YLErp.Modules.SwapModule
                 "The previous EOD identity must not be reset to a new position");
         }
 
+        [TestMethod]
+        public void DI_MANUAL_PREPAY_PARTIAL_CLOSE_UsesHistoryPlusRemainingDailyInterest()
+        {
+            var service = new StubEodPositionService();
+            var td = CreateTrade();
+            var position = CreateInterestPosition();
+            position.InterestMode = (int)InterestModeEnum.初始预付金;
+            position.InterestPrincipalFix = Principal;
+            var previousEod = CreatePreEod(StartDate.AddDays(2), 100m);
+            previousEod.InterestMode = position.InterestMode;
+            previousEod.TdInterestPrincipal = Principal;
+            var closeFlow = CreateSwapFlowEvent(StartDate.AddDays(3), 50m);
+            closeFlow.EventType = (int)SwapFlowEventTypeEnum.平仓;
+            closeFlow.InterestPrincipal = 500m;
+
+            var result = service.ExecuteSaveAutoEodWithCloseInterestPosition(
+                previousEod, position, td, StartDate.AddDays(3), null,
+                500m, 0m, new List<swap_flow_event> { closeFlow }, 500m, false);
+
+            var expected = previousEod.InterestIncomeSum
+                + result.TdInterestIncome - result.TdCloseInterest;
+            AssertDecimal(expected, result.InterestIncomeSum,
+                "预付金部分平仓待实现收益应为历史待实现+平仓后当日新增-平仓实现");
+        }
+
         [TestMethod]
         public void DI_AUTO_SETTLEMENT_005_AutoSettlementKeepsRemainingPrincipal()
         {
diff --git a/YLErpDAL/Modules/SwapModule/SwapEodPositionService.cs b/YLErpDAL/Modules/SwapModule/SwapEodPositionService.cs
index ce7e3807..5987acef 100644
--- a/YLErpDAL/Modules/SwapModule/SwapEodPositionService.cs
+++ b/YLErpDAL/Modules/SwapModule/SwapEodPositionService.cs
@@ -1412,8 +1412,14 @@ namespace YLErp.Modules.SwapModule
             }
             else
             {
+                var useAccrualBalance = !autoSwap
+                    && (position.InterestMode == (int)InterestModeEnum.初始预付金
+                        || position.InterestMode == (int)InterestModeEnum.追加预付金);
+                var pendingInterestBeforeSettlement = useAccrualBalance
+                    ? lastInterestIncomeSum + newEodPayPosition.TdInterestIncome
+                    : interestAmountBeforeSettlement;
                 newEodPayPosition.InterestIncomeSum = RoundEodInterest(
-                    interestAmountBeforeSettlement - newEodPayPosition.TdCloseInterest);
+                    pendingInterestBeforeSettlement - newEodPayPosition.TdCloseInterest);
                 newEodPayPosition.InterestFeeSum = eodPayPosition.InterestFeeSum + newEodPayPosition.TdInterestFee - newEodPayPosition.TdCloseInterestFee;
             }
             //持仓内容-利息腿-损益统计(本方视角）