diff --git a/app/Services/OfflineOrderService.php b/app/Services/OfflineOrderService.php
index 49806d12..9d234204 100644
--- a/app/Services/OfflineOrderService.php
+++ b/app/Services/OfflineOrderService.php
@@ -201,7 +201,7 @@ class OfflineOrderService
                 throw new BizException('商品总额不能小于0');
             }
 
-            $paymentAmount = $productsTotalAmount;
+            $discountReductionAmount = 0;
             if (is_numeric($item['discount'])) {
                 if ($item['discount'] <= 0) {
                     throw new BizException('折扣必须大于0');
@@ -209,14 +209,14 @@ class OfflineOrderService
                     throw new BizException('折扣必须小于10');
                 }
                 $discount = bcdiv($item['discount'], 10, 3);
-                $paymentAmount = round(bcmul($productsTotalAmount, $discount, 2));
+                $discountReductionAmount = bcsub($productsTotalAmount, round(bcmul($productsTotalAmount, $discount, 2)));
             }
 
             return [
                 'product_category_id' => $item['product_category_id'],
                 'products_total_amount' => (int) $productsTotalAmount,
-                'discount_reduction_amount' => (int) ($productsTotalAmount - $paymentAmount),
-                'payment_amount' => (int) $paymentAmount,
+                'discount_reduction_amount' => (int) $discountReductionAmount,
+                'payment_amount' => (int) ($productsTotalAmount - $discountReductionAmount),
             ];
         })->all();
     }