diff --git a/app/Services/PatientOrderService.php b/app/Services/PatientOrderService.php
index 6d1fef8..737696a 100644
--- a/app/Services/PatientOrderService.php
+++ b/app/Services/PatientOrderService.php
@@ -934,7 +934,20 @@ class PatientOrderService extends BaseService
             $result['amount_total'] = $order_product['amount_total']; // 订单金额
             $result['payment_amount_total'] = $order_product['payment_amount_total']; // 实际订单金额
             $result['coupon_amount_total'] = $order_product['coupon_amount_total']; // 优惠金额
-            $result['discount_amount'] = $order_product['amount_total'] - $order_product['coupon_amount_total'] + $order_product['logistics_fee'] - $order_product['payment_amount_total']; // 优惠金额
+            $result['discount_amount'] =
+                bcsub(
+                    bcadd(
+                        bcsub(
+                            $order_product['amount_total'],
+                            $order_product['coupon_amount_total'],
+                            2
+                        ),
+                        $order_product['logistics_fee'],
+                        2
+                    ),
+                    $order_product['payment_amount_total'],
+                    2
+                ); // 优惠金额
 
             // 获取优惠卷不可用原因。存在优惠卷，但是未使用-暂时废弃
             /*if ($order_product['coupon_amount_total'] == 0){