diff --git a/src/main/java/com/chaozhanggui/system/cashierservice/service/PayService.java b/src/main/java/com/chaozhanggui/system/cashierservice/service/PayService.java
index 489a943..5921213 100644
--- a/src/main/java/com/chaozhanggui/system/cashierservice/service/PayService.java
+++ b/src/main/java/com/chaozhanggui/system/cashierservice/service/PayService.java
@@ -1297,7 +1297,7 @@ public class PayService {
             throw new MsgException("退款金额必须大于0");
         }
 
-        oldOrderInfo.setCouponInfoList(JSONObject.toJSONString(couponInfoDTO));
+        oldOrderInfo.setCouponInfoList(couponInfoDTO == null ? null : JSONObject.toJSONString(couponInfoDTO));
 
         // 保存剩余未退款的订单详情
         if (!remainOrderDetailList.isEmpty()) {