diff --git a/app/Models/Order.php b/app/Models/Order.php
index dda0581..fea63ee 100755
--- a/app/Models/Order.php
+++ b/app/Models/Order.php
@@ -18,7 +18,7 @@ use Illuminate\Database\Eloquent\Relations\HasMany;
  * @property int $total_amount
  * @property int|null $handling_amount
  * @property int|null $balance_amount
- * @property int|null $refund_amount
+ * @property int|null $surplus_credit
  * @property int|null $surplus_amount
  * @property int $type
  * @property int $status
diff --git a/app/Services/OrderService.php b/app/Services/OrderService.php
index 900be59..1761315 100644
--- a/app/Services/OrderService.php
+++ b/app/Services/OrderService.php
@@ -103,8 +103,8 @@ class OrderService
         DB::transaction(function () use ($order, $plan) {
             $this->user = User::lockForUpdate()->find($order->user_id);
 
-            if ($order->refund_amount) {
-                $this->user->balance += $order->refund_amount;
+            if ($order->surplus_credit) {
+                $this->user->balance += $order->surplus_credit;
             }
 
             if ($order->surplus_order_ids) {
@@ -158,7 +158,7 @@ class OrderService
             if ((int) admin_setting('surplus_enable', 1))
                 $this->getSurplusValue($user, $order);
             if ($order->surplus_amount >= $order->total_amount) {
-                $order->refund_amount = (int) ($order->surplus_amount - $order->total_amount);
+                $order->surplus_credit = (int) ($order->surplus_amount - $order->total_amount);
                 $order->total_amount = 0;
             } else {
                 $order->total_amount = (int) ($order->total_amount - $order->surplus_amount);
@@ -256,7 +256,7 @@ class OrderService
                 return;
             }
 
-            $orderAmountSum = $orders->sum(fn($item) => $item->total_amount + $item->balance_amount + $item->surplus_amount - $item->refund_amount);
+            $orderAmountSum = $orders->sum(fn($item) => $item->total_amount + $item->balance_amount + $item->surplus_amount - $item->surplus_credit);
             $orderMonthSum = $orders->sum(fn($item) => self::STR_TO_TIME[PlanService::getPeriodKey($item->period)] ?? 0);
             $firstOrderAt = $orders->min('created_at');
             $expiredAt = Carbon::createFromTimestamp($firstOrderAt)->addMonths($orderMonthSum);
diff --git a/database/migrations/2026_05_30_000000_rename_refund_amount_to_surplus_credit.php b/database/migrations/2026_05_30_000000_rename_refund_amount_to_surplus_credit.php
new file mode 100644
index 0000000..e60af2c
--- /dev/null
+++ b/database/migrations/2026_05_30_000000_rename_refund_amount_to_surplus_credit.php
@@ -0,0 +1,22 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    public function up(): void
+    {
+        Schema::table('v2_order', function (Blueprint $table) {
+            $table->renameColumn('refund_amount', 'surplus_credit');
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::table('v2_order', function (Blueprint $table) {
+            $table->renameColumn('surplus_credit', 'refund_amount');
+        });
+    }
+};
\ No newline at end of file