diff --git a/resources/views/admin/plans/index.blade.php b/resources/views/admin/plans/index.blade.php
index 729a9b7..30ffa82 100644
--- a/resources/views/admin/plans/index.blade.php
+++ b/resources/views/admin/plans/index.blade.php
@@ -142,6 +142,9 @@
 <div class="card mb-20">
     <h3>筛选条件</h3>
     <form method="get" action="/admin/plans" class="grid-3">
+        @if($safeBackForLinks !== '')
+            <input type="hidden" name="back" value="{!! $safeBackForLinks !!}">
+        @endif
         <select name="status">
             <option value="">全部状态</option>
             @foreach(($filterOptions['statuses'] ?? []) as $value => $label)
diff --git a/tests/Feature/AdminPlanIndexFilterFormDropsUnsafeBackTest.php b/tests/Feature/AdminPlanIndexFilterFormDropsUnsafeBackTest.php
new file mode 100644
index 0000000..2c1ed39
--- /dev/null
+++ b/tests/Feature/AdminPlanIndexFilterFormDropsUnsafeBackTest.php
@@ -0,0 +1,35 @@
+<?php
+
+namespace Tests\Feature;
+
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\TestCase;
+
+class AdminPlanIndexFilterFormDropsUnsafeBackTest extends TestCase
+{
+    use RefreshDatabase;
+
+    protected function loginAsPlatformAdmin(): void
+    {
+        $this->seed();
+
+        $this->post('/admin/login', [
+            'email' => 'platform.admin@demo.local',
+            'password' => 'Platform@123456',
+        ])->assertRedirect('/admin');
+    }
+
+    public function test_index_filter_form_should_drop_unsafe_back_as_hidden_input(): void
+    {
+        $this->loginAsPlatformAdmin();
+
+        // 外链 back：必须丢弃（非 / 开头）
+        $back = 'https://evil.test/a';
+
+        $res = $this->get('/admin/plans?back=' . urlencode($back));
+        $res->assertOk();
+
+        $res->assertDontSee('name="back"', false);
+        $res->assertDontSee('value="' . $back . '"', false);
+    }
+}
diff --git a/tests/Feature/AdminPlanIndexFilterFormKeepsSafeBackTest.php b/tests/Feature/AdminPlanIndexFilterFormKeepsSafeBackTest.php
new file mode 100644
index 0000000..b511327
--- /dev/null
+++ b/tests/Feature/AdminPlanIndexFilterFormKeepsSafeBackTest.php
@@ -0,0 +1,33 @@
+<?php
+
+namespace Tests\Feature;
+
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\TestCase;
+
+class AdminPlanIndexFilterFormKeepsSafeBackTest extends TestCase
+{
+    use RefreshDatabase;
+
+    protected function loginAsPlatformAdmin(): void
+    {
+        $this->seed();
+
+        $this->post('/admin/login', [
+            'email' => 'platform.admin@demo.local',
+            'password' => 'Platform@123456',
+        ])->assertRedirect('/admin');
+    }
+
+    public function test_index_filter_form_should_keep_safe_back_as_hidden_input(): void
+    {
+        $this->loginAsPlatformAdmin();
+
+        $back = '/admin/platform-orders?plan_id=3&status=pending';
+
+        $res = $this->get('/admin/plans?back=' . urlencode($back));
+        $res->assertOk();
+
+        $res->assertSee('name="back" value="' . $back . '"', false);
+    }
+}