diff --git a/api/service/OrderSingle.go b/api/service/OrderSingle.go
index 342b149..22494cf 100644
--- a/api/service/OrderSingle.go
+++ b/api/service/OrderSingle.go
@@ -131,6 +131,9 @@ func (r *OrderSingleService) AddOrderSingle(tx *gorm.DB, UserId, QuestionId int6
 
 		// 实际付款金额
 		paymentAmountTotal = amountTotal - couponAmountTotal
+		if paymentAmountTotal < 0 {
+			paymentAmountTotal = 0
+		}
 		if *orderPrice != paymentAmountTotal {
 			return nil, errors.New("价格异常")
 		}