.

soss-system/src/main/java/com/soss/system/service/impl/CouponUserServiceImpl.java

@@ -229,7 +229,11 @@ public class CouponUserServiceImpl implements ICouponUserService {
                 orderDetails.forEach(orderDetail -> {
                     BigDecimal couponAmount = couponAmountMap.get(orderDetail.getSkuId());
                     orderDetail.setCouponAmount(couponAmount == null ? BigDecimal.ZERO : couponAmount.negate());
-                    orderDetail.setRealAmount(orderDetail.getAmountShould().add(orderDetail.getCouponAmount()));
+                    if (orderDetail.getAmountShould().add(orderDetail.getCouponAmount()).compareTo(BigDecimal.ZERO) < 0) {
+                        orderDetail.setRealAmount(BigDecimal.ZERO);
+                    } else {
+                        orderDetail.setRealAmount(orderDetail.getAmountShould().add(orderDetail.getCouponAmount()));
+                    }
                 });
             }
         });