diff --git a/app/Support/BackUrl.php b/app/Support/BackUrl.php
index feccdff..cd8a738 100644
--- a/app/Support/BackUrl.php
+++ b/app/Support/BackUrl.php
@@ -133,4 +133,21 @@ class BackUrl
 
         return $path . '?' . \Illuminate\Support\Arr::query($q);
     }
+
+    /**
+     * 生成当前页面去掉 back 后的 selfWithoutBack（站内相对路径）。
+     * 用于：生成返回来源 back 或防止 back 嵌套膨胀。
+     */
+    public static function selfWithoutBack(): string
+    {
+        $currentQuery = request()->query();
+        unset($currentQuery['back']);
+
+        $url = '/' . ltrim(request()->path(), '/');
+        if (count($currentQuery) > 0) {
+            $url .= '?' . \Illuminate\Support\Arr::query($currentQuery);
+        }
+
+        return $url;
+    }
 }
diff --git a/resources/views/admin/plans/index.blade.php b/resources/views/admin/plans/index.blade.php
index e4b08a9..63c029d 100644
--- a/resources/views/admin/plans/index.blade.php
+++ b/resources/views/admin/plans/index.blade.php
@@ -6,12 +6,7 @@
 @section('content')
 @php
     // back 参数用于“返回上一页（保留上下文）”，但 back 本身不应再包含 back（避免无限嵌套导致 URL 膨胀）
-    $currentQuery = request()->query();
-    unset($currentQuery['back']);
-    $selfWithoutBack = '/' . ltrim(request()->path(), '/');
-    if (count($currentQuery) > 0) {
-        $selfWithoutBack .= '?' . \Illuminate\Support\Arr::query($currentQuery);
-    }
+    $selfWithoutBack = \App\Support\BackUrl::selfWithoutBack();
 
     // 用于构建“从套餐页跳转到订阅/订单页后可返回套餐页”的链接
     $makeSubscriptionUrl = function (array $query) use ($selfWithoutBack) {
diff --git a/resources/views/admin/platform_leads/index.blade.php b/resources/views/admin/platform_leads/index.blade.php
index f6facd2..6d93e7f 100644
--- a/resources/views/admin/platform_leads/index.blade.php
+++ b/resources/views/admin/platform_leads/index.blade.php
@@ -17,12 +17,7 @@
         : '';
 
     // back 参数用于“返回上一页（保留上下文）”，但 back 本身不应再包含 back（避免无限嵌套导致 URL 膨胀）
-    $currentQuery = request()->query();
-    unset($currentQuery['back']);
-    $selfWithoutBack = '/' . ltrim(request()->path(), '/');
-    if (count($currentQuery) > 0) {
-        $selfWithoutBack .= '?' . \Illuminate\Support\Arr::query($currentQuery);
-    }
+    $selfWithoutBack = \App\Support\BackUrl::selfWithoutBack();
 
     // 从线索直达“创建平台订单”入口：预填 plan_id/remark，并带 back 回到当前线索列表（保留筛选）
     // 备注：如果线索 meta 中包含 merchant_id，也会一并预填（用于“已存在站点，但需补单/续费”的场景）
diff --git a/resources/views/admin/platform_orders/index.blade.php b/resources/views/admin/platform_orders/index.blade.php
index 0c69493..036db58 100644
--- a/resources/views/admin/platform_orders/index.blade.php
+++ b/resources/views/admin/platform_orders/index.blade.php
@@ -10,12 +10,10 @@
     $SYNC_FAILED_REASON_TRUNCATE_LEN = (int) config('saasshop.platform_orders.sync_failed_reason_display_truncate_len', 60);
 
     // back 参数用于“返回上一页（保留上下文）”，但 back 本身不应再包含 back（避免无限嵌套导致 URL 膨胀）
+    $selfWithoutBack = \App\Support\BackUrl::selfWithoutBack();
+
     $currentQuery = request()->query();
     unset($currentQuery['back']);
-    $selfWithoutBack = '/' . ltrim(request()->path(), '/');
-    if (count($currentQuery) > 0) {
-        $selfWithoutBack .= '?' . \Illuminate\Support\Arr::query($currentQuery);
-    }
 
     // back 安全护栏（全页通用）：
     // - 仅允许站内相对路径（/ 开头）
diff --git a/resources/views/admin/site_subscriptions/index.blade.php b/resources/views/admin/site_subscriptions/index.blade.php
index 28b9845..18e1024 100644
--- a/resources/views/admin/site_subscriptions/index.blade.php
+++ b/resources/views/admin/site_subscriptions/index.blade.php
@@ -7,12 +7,10 @@
 @php
     // back 参数用于“返回上一页（保留上下文）”，但 back 本身不应再包含 back（避免无限嵌套导致 URL 膨胀）
     // 注意：使用相对路径而非绝对 URL，避免不同 APP_URL 环境影响，以及 show 页 back 安全校验（要求以 / 开头）
+    $selfWithoutBack = \App\Support\BackUrl::selfWithoutBack();
+
     $currentQuery = request()->query();
     unset($currentQuery['back']);
-    $selfWithoutBack = '/' . ltrim(request()->path(), '/');
-    if (count($currentQuery) > 0) {
-        $selfWithoutBack .= '?' . \Illuminate\Support\Arr::query($currentQuery);
-    }
     $back = $selfWithoutBack;
 
     // 用于构建“保留当前筛选上下文”的站内跳转链接（且不透传 back，避免嵌套/污染）
diff --git a/resources/views/admin/site_subscriptions/show.blade.php b/resources/views/admin/site_subscriptions/show.blade.php
index 598a0b6..4218f28 100644
--- a/resources/views/admin/site_subscriptions/show.blade.php
+++ b/resources/views/admin/site_subscriptions/show.blade.php
@@ -11,12 +11,7 @@
     $platformOrdersBaseUrl = '/admin/platform-orders';
 
     // back 参数用于“返回上一页（保留上下文）”，但 back 本身不应再包含 back（避免无限嵌套导致 URL 膨胀）
-    $currentQuery = request()->query();
-    unset($currentQuery['back']);
-    $selfWithoutBack = '/' . ltrim(request()->path(), '/');
-    if (count($currentQuery) > 0) {
-        $selfWithoutBack .= '?' . \Illuminate\Support\Arr::query($currentQuery);
-    }
+    $selfWithoutBack = \App\Support\BackUrl::selfWithoutBack();
 
     $makePlatformOrderUrl = function (array $query) use ($platformOrdersBaseUrl, $selfWithoutBack) {
         // 若调用方显式传了 back，则不覆盖；否则默认回到当前订阅详情页（剔除 back，避免嵌套）