diff --git a/src/main/java/com/ycwl/basic/pricing/mapper/PriceCouponConfigMapper.java b/src/main/java/com/ycwl/basic/pricing/mapper/PriceCouponConfigMapper.java
index 7e491dc6..00de5da6 100644
--- a/src/main/java/com/ycwl/basic/pricing/mapper/PriceCouponConfigMapper.java
+++ b/src/main/java/com/ycwl/basic/pricing/mapper/PriceCouponConfigMapper.java
@@ -33,10 +33,12 @@ public interface PriceCouponConfigMapper extends BaseMapper<PriceCouponConfig> {
     PriceCouponConfig selectValidCouponById(Long couponId);
     
     /**
-     * 增加优惠券使用数量
+     * 增加优惠券使用数量（支持无限量优惠券）
+     * 当 total_quantity 为 NULL 或 <= 0 时表示不限制使用数量
      */
-    @Update("UPDATE price_coupon_config SET used_quantity = used_quantity + 1, " +
-            "update_time = NOW() WHERE id = #{couponId} AND used_quantity < total_quantity")
+    @Update("UPDATE price_coupon_config SET used_quantity = COALESCE(used_quantity, 0) + 1, " +
+            "update_time = NOW() WHERE id = #{couponId} " +
+            "AND (total_quantity IS NULL OR total_quantity <= 0 OR COALESCE(used_quantity, 0) < total_quantity)")
     int incrementUsedQuantity(Long couponId);
 
     /**