diff --git a/tests/Feature/AdminPlatformOrderIndexQuickFilterAllShouldKeepBackAndClearFiltersTest.php b/tests/Feature/AdminPlatformOrderIndexQuickFilterAllShouldKeepBackAndClearFiltersTest.php
new file mode 100644
index 0000000..eecadf3
--- /dev/null
+++ b/tests/Feature/AdminPlatformOrderIndexQuickFilterAllShouldKeepBackAndClearFiltersTest.php
@@ -0,0 +1,49 @@
+<?php
+
+namespace Tests\Feature;
+
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\TestCase;
+
+class AdminPlatformOrderIndexQuickFilterAllShouldKeepBackAndClearFiltersTest 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_platform_orders_index_quick_filter_all_should_keep_back_and_clear_filters(): void
+    {
+        $this->loginAsPlatformAdmin();
+
+        $res = $this->get('/admin/platform-orders?merchant_id=1&reconcile_mismatch=1&back=/admin');
+        $res->assertOk();
+
+        $html = (string) $res->getContent();
+
+        $this->assertMatchesRegularExpression('/<a[^>]*data-role="po-quickfilter-all"[^>]*href="([^"]+)"/u', $html);
+        preg_match('/<a[^>]*data-role="po-quickfilter-all"[^>]*href="([^"]+)"/u', $html, $m);
+
+        $href = html_entity_decode($m[1] ?? '');
+        $this->assertNotEmpty($href);
+
+        $this->assertSame('/admin/platform-orders', (string) parse_url($href, PHP_URL_PATH));
+
+        $query = parse_url($href, PHP_URL_QUERY) ?: '';
+        parse_str($query, $q);
+
+        $this->assertSame('/admin', (string) ($q['back'] ?? ''));
+        $this->assertArrayNotHasKey('merchant_id', $q);
+        $this->assertArrayNotHasKey('reconcile_mismatch', $q);
+
+        // 避免 Blade 把 back 参数 escape 成 &amp;back= 导致 back 被错误编码/叠加
+        $res->assertDontSee('&amp;back=', false);
+    }
+}