diff --git a/UnitTestProject/Modules/SwapModule/Margin/SwapAdditionalMarginLegTest.cs b/UnitTestProject/Modules/SwapModule/Margin/SwapAdditionalMarginLegTest.cs
index 60de9711..0c091bd1 100644
--- a/UnitTestProject/Modules/SwapModule/Margin/SwapAdditionalMarginLegTest.cs
+++ b/UnitTestProject/Modules/SwapModule/Margin/SwapAdditionalMarginLegTest.cs
@@ -54,6 +54,12 @@ namespace YLErp.Modules.SwapModule
             //两位 AwayFromZero 舍入
             var rounded = SwapAdditionalMarginService.BuildEodMarginLeg(td, 1000.005, SettleDate, optId: 0);
             Assert.AreEqual(1000.01m, rounded.InterestPrincipalFix);
+
+            //币种：取交易结算币种；交易未设置时回退系统默认 CNY（与存量手工腿口径一致，2026-08-27 修复空币种）
+            Assert.AreEqual("CNY", leg.Currency);
+            td.SettlementCurrency = null;
+            Assert.AreEqual(ConsGlobal.Currency.CNY,
+                SwapAdditionalMarginService.BuildEodMarginLeg(td, 100, SettleDate, optId: 0).Currency);
         }
 
         /// <summary>
diff --git a/YLErpDAL/Modules/SwapModule/Margin/SwapAdditionalMarginService.cs b/YLErpDAL/Modules/SwapModule/Margin/SwapAdditionalMarginService.cs
index 95bf5f32..02b31082 100644
--- a/YLErpDAL/Modules/SwapModule/Margin/SwapAdditionalMarginService.cs
+++ b/YLErpDAL/Modules/SwapModule/Margin/SwapAdditionalMarginService.cs
@@ -69,7 +69,7 @@ namespace YLErp.Modules.SwapModule.Margin
                 HappenDate = settleDate,
                 PosiStartDate = td.StartDate ?? settleDate,
                 PosiMatuirityDate = td.ExerciseDate,
-                Currency = td.SettlementCurrency,
+                Currency = td.SettlementCurrency ?? ConsGlobal.Currency.CNY,
                 FundTag = null,
                 OptId = optId,
                 OptName = EodOptName,