diff --git a/app/constants/errorcode/error_code.go b/app/constants/errorcode/error_code.go
index 2f7170e..39aaee3 100644
--- a/app/constants/errorcode/error_code.go
+++ b/app/constants/errorcode/error_code.go
@@ -87,6 +87,9 @@ const (
 	PreRefundFail = 1702
 
 	ThirdRefundFail = 1710
+
+	// 退款
+	RefundOutTradeNoSame = 1801
 )
 
 var MsgEN = map[int]string{
@@ -160,6 +163,7 @@ var MsgZH = map[int]string{
 	PreRefundFail:               "创建退款单失败",
 	OrderNotSupportRefundPart:   "订单暂不支持部分退款",
 	OrderRefundAmountError:      "退款金额错误",
+	RefundOutTradeNoSame:        "支付商户单号和退款商户单号不能相同",
 
 	ThirdRefundFail: "第三方退款失败",
 }
diff --git a/app/services/thirdpay/do/pay.go b/app/services/thirdpay/do/pay.go
index 308112e..f2a32ed 100644
--- a/app/services/thirdpay/do/pay.go
+++ b/app/services/thirdpay/do/pay.go
@@ -55,7 +55,7 @@ func NewPayWithPayCheck(paycheck *PayCheck) *Pay {
 
 func (w *Pay) CheckRefundOrder() bool {
 	cond := builder.NewCond()
-	cond = cond.And(builder.Eq{"app_id": w.PayParam.App_id}, builder.Eq{"out_trade_no": w.PayParam.OutTradeNo})
+	cond = cond.And(builder.Eq{"app_id": w.PayParam.App_id}, builder.Eq{"order_type": common.ORDER_TYPE_REFUND}, builder.Eq{"out_trade_no": w.PayParam.OutTradeNo})
 	order, code := services.OrderFindOne(&ordersmodel.Orders{}, cond)
 	if code != errorcode.Success {
 		return true
diff --git a/app/services/thirdpay/do/pay_check.go b/app/services/thirdpay/do/pay_check.go
index 6f5142e..22ab448 100644
--- a/app/services/thirdpay/do/pay_check.go
+++ b/app/services/thirdpay/do/pay_check.go
@@ -80,6 +80,7 @@ func (w *PayCheck) CheckOrderPay() {
 }
 
 func (w *PayCheck) CheckOrderRefund() (order *ordersmodel.Orders) {
+	// 查询原来的支付单
 	w.GetOldOrder(&types.OrderFindOne{
 		OutTradeNo: w.Reqs.RefundOutTradeNo,
 		OrderId:    w.Reqs.RefundOrderId,
diff --git a/app/services/thirdpay/pay.go b/app/services/thirdpay/pay.go
index 0d95185..24ba937 100644
--- a/app/services/thirdpay/pay.go
+++ b/app/services/thirdpay/pay.go
@@ -48,6 +48,10 @@ func ThirdPayInfoCheck(ctx context.Context, payReq *front.PayReqs, appCheck *ser
 
 func ThirdPayRefundCheck(ctx context.Context, refundReq *front.RefundReqs, appCheck *services.AppCheck, ip string) (check *thirdpay.PayCheck, errorCode int) {
 	var req types.Reqs
+	// 外部商户单号，支付商户单号和退款商户单号不能相同
+	if refundReq.OutTradeNo == refundReq.RefundOutTradeNo {
+		return check, errorcode.RefundOutTradeNoSame
+	}
 	copier.Copy(&req, refundReq)
 	check = thirdpay.NewPayCheck(&ctx, &req, appCheck, ip)
 	// 校验表单