diff --git a/app/Support/BackUrl.php b/app/Support/BackUrl.php
index b92997c..feccdff 100644
--- a/app/Support/BackUrl.php
+++ b/app/Support/BackUrl.php
@@ -68,6 +68,30 @@ class BackUrl
         return $url;
     }
 
+    /**
+     * 给指定站内相对路径附加安全 back（若 back 为空则原样返回）。
+     *
+     * 用途：列表页“全部/返回来源”等需要清空筛选但保留 back 的场景。
+     */
+    public static function withBack(string $path, string $safeBackForLinks = ''): string
+    {
+        $path = (string) $path;
+
+        if ($safeBackForLinks === '') {
+            return $path;
+        }
+
+        // 仅支持站内相对路径；若调用方传入了异常值，这里不做拼接，直接返回原 path。
+        if ($path === '' || !str_starts_with($path, '/')) {
+            return $path;
+        }
+
+        // 若 path 已带 query，则追加 &back=；否则追加 ?back=
+        $sep = str_contains($path, '?') ? '&' : '?';
+
+        return $path . $sep . \Illuminate\Support\Arr::query(['back' => $safeBackForLinks]);
+    }
+
     /**
      * 当前路径下的“快捷筛选”链接构造器：
      * - 仅保留指定上下文键（例如 merchant_id/plan_id/keyword/lead_id 等）
diff --git a/resources/views/admin/plans/index.blade.php b/resources/views/admin/plans/index.blade.php
index 1a1bbae..e4b08a9 100644
--- a/resources/views/admin/plans/index.blade.php
+++ b/resources/views/admin/plans/index.blade.php
@@ -55,10 +55,7 @@
         };
 
         // “全部”：清空筛选，但保留安全 back（用于返回来源页）
-        $allUrl = '/admin/plans';
-        if ($safeBackForLinks !== '') {
-            $allUrl .= '?' . \Illuminate\Support\Arr::query(['back' => $safeBackForLinks]);
-        }
+        $allUrl = \App\Support\BackUrl::withBack('/admin/plans', $safeBackForLinks);
     @endphp
 
     <div>
diff --git a/resources/views/admin/platform_orders/index.blade.php b/resources/views/admin/platform_orders/index.blade.php
index baa9fa6..0c69493 100644
--- a/resources/views/admin/platform_orders/index.blade.php
+++ b/resources/views/admin/platform_orders/index.blade.php
@@ -141,10 +141,7 @@
 
         // “全部”：清空筛选，但保留 back（用于返回来源页）
         // “全部”：清空筛选，但保留安全 back（用于返回来源页）
-        $allUrl = '/admin/platform-orders';
-        if ($safeBackForLinks !== '') {
-            $allUrl .= '?' . \Illuminate\Support\Arr::query(['back' => $safeBackForLinks]);
-        }
+        $allUrl = \App\Support\BackUrl::withBack('/admin/platform-orders', $safeBackForLinks);
     @endphp
 
     <div class="inline-links">
diff --git a/resources/views/admin/site_subscriptions/index.blade.php b/resources/views/admin/site_subscriptions/index.blade.php
index 6b52ba5..28b9845 100644
--- a/resources/views/admin/site_subscriptions/index.blade.php
+++ b/resources/views/admin/site_subscriptions/index.blade.php
@@ -63,10 +63,7 @@
         };
 
         // “全部”：清空筛选，但保留安全 back（用于返回来源页）
-        $allUrl = '/admin/site-subscriptions';
-        if ($safeBackForLinks !== '') {
-            $allUrl .= '?' . \Illuminate\Support\Arr::query(['back' => $safeBackForLinks]);
-        }
+        $allUrl = \App\Support\BackUrl::withBack('/admin/site-subscriptions', $safeBackForLinks);
     @endphp
 
     <div>