diff --git a/tests/Feature/AdminPlatformOrderShowIndexLinkKeepsContextTest.php b/tests/Feature/AdminPlatformOrderShowIndexLinkKeepsContextTest.php
index 740da79..49b1992 100644
--- a/tests/Feature/AdminPlatformOrderShowIndexLinkKeepsContextTest.php
+++ b/tests/Feature/AdminPlatformOrderShowIndexLinkKeepsContextTest.php
@@ -84,4 +84,53 @@ class AdminPlatformOrderShowIndexLinkKeepsContextTest extends TestCase
         $res3->assertSee('← 返回上一页（保留上下文）');
         $res3->assertDontSee('返回平台订单列表（保留上下文）');
     }
+
+    public function test_show_page_should_fall_back_to_platform_order_index_link_with_self_back_when_back_is_unsafe(): void
+    {
+        $this->loginAsPlatformAdmin();
+
+        $merchant = Merchant::query()->firstOrFail();
+
+        $plan = Plan::query()->create([
+            'code' => 'po_show_index_link_unsafe_back_plan',
+            'name' => '平台订单详情 unsafe back 兜底返回测试套餐',
+            'billing_cycle' => 'monthly',
+            'price' => 10,
+            'list_price' => 10,
+            'status' => 'active',
+            'sort' => 10,
+            'published_at' => now(),
+        ]);
+
+        $order = PlatformOrder::query()->create([
+            'merchant_id' => $merchant->id,
+            'plan_id' => $plan->id,
+            'order_no' => 'PO_SHOW_INDEX_LINK_UNSAFE_BACK_0001',
+            'order_type' => 'new_purchase',
+            'status' => 'pending',
+            'payment_status' => 'unpaid',
+            'plan_name' => $plan->name,
+            'billing_cycle' => $plan->billing_cycle,
+            'period_months' => 1,
+            'quantity' => 1,
+            'payable_amount' => 10,
+            'paid_amount' => 0,
+            'placed_at' => now(),
+            'meta' => [],
+        ]);
+
+        $unsafeBack = '/admin/platform-orders?status=pending&back=/admin';
+
+        $res = $this->get('/admin/platform-orders/' . $order->id . '?back=' . urlencode($unsafeBack));
+        $res->assertOk();
+
+        $expectedIndexUrl = '/admin/platform-orders?' . Arr::query([
+            'back' => '/admin/platform-orders/' . $order->id,
+        ]);
+
+        $res->assertDontSee('← 返回上一页（保留上下文）');
+        $res->assertSee('返回平台订单列表（保留上下文）');
+        $res->assertSee($expectedIndexUrl, false);
+        $res->assertDontSee('back=' . $unsafeBack, false);
+    }
 }