diff --git a/app/Models/UserCoupon.php b/app/Models/UserCoupon.php
index 9ada496f..56c6c67a 100644
--- a/app/Models/UserCoupon.php
+++ b/app/Models/UserCoupon.php
@@ -176,13 +176,15 @@ class UserCoupon extends Model
     public function getDiscountAmount(int $total)
     {
         $couponDiscount = 0;
-        // 优惠券: 直接抵扣
-        if ($this->coupon_type == Coupon::TYPE_AMOUNT) {
-            $couponDiscount = $this->coupon_amount;
-        }
-        // 优惠券: 折扣
-        else if ($this->coupon_type == Coupon::TYPE_DISCOUNT) {
-            $couponDiscount = (int) bcmul($total, bcdiv(100 - $this->coupon_amount, 100, 2));
+        if ($this->coupon_amount > 0) {
+            // 优惠券: 直接抵扣
+            if ($this->coupon_type == Coupon::TYPE_AMOUNT) {
+                $couponDiscount = $this->coupon_amount;
+            }
+            // 优惠券: 折扣
+            else if ($this->coupon_type == Coupon::TYPE_DISCOUNT) {
+                $couponDiscount = (int) bcmul($total, bcdiv(100 - $this->coupon_amount, 100, 2));
+            }
         }
 
         return $couponDiscount;