diff --git a/tests/Feature/AdminPlatformOrderCreateDefaultsPreselectedTest.php b/tests/Feature/AdminPlatformOrderCreateDefaultsPreselectedTest.php
new file mode 100644
index 0000000..4e4acb0
--- /dev/null
+++ b/tests/Feature/AdminPlatformOrderCreateDefaultsPreselectedTest.php
@@ -0,0 +1,80 @@
+<?php
+
+namespace Tests\Feature;
+
+use App\Models\Merchant;
+use App\Models\Plan;
+use App\Models\SiteSubscription;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\TestCase;
+
+class AdminPlatformOrderCreateDefaultsPreselectedTest 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_create_form_can_preselect_merchant_plan_and_order_type_from_query_defaults(): void
+    {
+        $this->loginAsPlatformAdmin();
+
+        $merchant = Merchant::query()->firstOrFail();
+        $plan = Plan::query()->create([
+            'code' => 'create_defaults_preselect_plan',
+            'name' => '创建订单默认值预选测试套餐',
+            'billing_cycle' => 'monthly',
+            'price' => 100,
+            'list_price' => 100,
+            'status' => 'active',
+            'sort' => 10,
+            'published_at' => now(),
+        ]);
+
+        $sub = SiteSubscription::query()->create([
+            'merchant_id' => $merchant->id,
+            'plan_id' => $plan->id,
+            'status' => 'activated',
+            'source' => 'manual',
+            'subscription_no' => 'SUB_CREATE_DEFAULTS_0001',
+            'plan_name' => $plan->name,
+            'billing_cycle' => $plan->billing_cycle,
+            'period_months' => 1,
+            'amount' => 100,
+            'starts_at' => now()->subDay(),
+            'ends_at' => now()->addMonth(),
+            'activated_at' => now()->subDay(),
+        ]);
+
+        $url = '/admin/platform-orders/create?merchant_id=' . $merchant->id
+            . '&plan_id=' . $plan->id
+            . '&site_subscription_id=' . $sub->id
+            . '&order_type=renewal'
+            . '&quantity=2'
+            . '&discount_amount=3.5'
+            . '&payment_channel=offline'
+            . '&remark=' . urlencode('来自订阅：' . $sub->subscription_no);
+
+        $res = $this->get($url);
+        $res->assertOk();
+
+        // 预选 merchant/plan/order_type
+        $res->assertSee('<option value="' . $merchant->id . '" selected>', false);
+        $res->assertSee('<option value="' . $plan->id . '" selected>', false);
+        $res->assertSee('<option value="renewal" selected>', false);
+
+        // 预填其它字段
+        $res->assertSee('name="site_subscription_id" value="' . $sub->id . '"', false);
+        $res->assertSee('name="quantity" value="2"', false);
+        $res->assertSee('name="discount_amount" value="3.5"', false);
+        $res->assertSee('name="payment_channel" value="offline"', false);
+        $res->assertSee('来自订阅：' . $sub->subscription_no, false);
+    }
+}