update

src/main/java/com/gogirl/domain/order/serve/OrderServe.java

@@ -204,7 +204,7 @@ public class OrderServe implements Serializable {
 
     public void addDiscountPrice(BigDecimal discountPrice) {
         this.discountPrice = this.discountPrice.add(discountPrice);
-        this.payPrice = this.price.subtract(discountPrice);
+        this.payPrice = this.payPrice.subtract(discountPrice);
     }
 
     public void calcPrice() {