diff --git a/src/main/java/com/chaozhanggui/system/cashierservice/entity/TbCashierCart.java b/src/main/java/com/chaozhanggui/system/cashierservice/entity/TbCashierCart.java
index f53a3e9..9847dae 100644
--- a/src/main/java/com/chaozhanggui/system/cashierservice/entity/TbCashierCart.java
+++ b/src/main/java/com/chaozhanggui/system/cashierservice/entity/TbCashierCart.java
@@ -100,11 +100,14 @@ public class TbCashierCart implements Serializable {
         if ("true".equals(isGift)) {
             totalAmount = packFee;
         } else {
+            discountSaleAmount = discountSaleAmount == null ? BigDecimal.ZERO : discountSaleAmount;
+            BigDecimal subtract;
             if (isMember != null && isMember == 1 && memberPrice != null && memberPrice.compareTo(BigDecimal.ZERO) > 0) {
-                totalAmount = totalNumber.multiply(memberPrice).add(packFee);
+                subtract = memberPrice.subtract(discountSaleAmount);
             } else {
-                totalAmount = totalNumber.multiply(discountSaleAmount != null ? discountSaleAmount : salePrice).add(packFee);
+                subtract = salePrice.subtract(discountSaleAmount);
             }
+            totalAmount = totalNumber.multiply(subtract.compareTo(BigDecimal.ZERO) < 0 ? BigDecimal.ZERO : subtract).add(packFee);
         }
     }