diff --git a/resources/views/admin/site_subscriptions/show.blade.php b/resources/views/admin/site_subscriptions/show.blade.php
index f7ae22a..44b673b 100644
--- a/resources/views/admin/site_subscriptions/show.blade.php
+++ b/resources/views/admin/site_subscriptions/show.blade.php
@@ -339,7 +339,8 @@
         @php
             $bmpaFailedReasonStats = $bmpaFailedReasonStats ?? [];
             // 避免 URL 过长/特殊字符破坏 query：原因过长则不生成 keyword 链接
-            $FAILED_REASON_KEYWORD_MAX_LEN = 80;
+            // 与列表页/仪表盘/订单详情保持一致：由 config 统一控制阈值。
+            $FAILED_REASON_KEYWORD_MAX_LEN = (int) config('saasshop.platform_orders.sync_error_keyword_link_max_len', 200);
         @endphp
         @if(count($bmpaFailedReasonStats) > 0)
             <div class="muted mt-6">
diff --git a/tests/Feature/AdminSiteSubscriptionShowFailedReasonTop3KeywordLinkMaxLenShouldUseConfigTest.php b/tests/Feature/AdminSiteSubscriptionShowFailedReasonTop3KeywordLinkMaxLenShouldUseConfigTest.php
new file mode 100644
index 0000000..29c5b4d
--- /dev/null
+++ b/tests/Feature/AdminSiteSubscriptionShowFailedReasonTop3KeywordLinkMaxLenShouldUseConfigTest.php
@@ -0,0 +1,113 @@
+<?php
+
+namespace Tests\Feature;
+
+use App\Models\Admin;
+use App\Models\Merchant;
+use App\Models\Plan;
+use App\Models\SiteSubscription;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\TestCase;
+
+class AdminSiteSubscriptionShowFailedReasonTop3KeywordLinkMaxLenShouldUseConfigTest 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_site_subscription_show_failed_reason_top3_keyword_link_max_len_should_use_config(): void
+    {
+        // 将阈值设为 5：len=5 应生成 keyword 链接；len=6 不生成
+        config()->set('saasshop.platform_orders.sync_error_keyword_link_max_len', 5);
+
+        $this->loginAsPlatformAdmin();
+
+        $merchantId = (int) Merchant::query()->value('id');
+        $platformAdminId = (int) Admin::query()->where('email', 'platform.admin@demo.local')->value('id');
+
+        $plan = Plan::query()->create([
+            'code' => 'sub_show_failed_reason_len_plan',
+            'name' => '订阅详情原因阈值配置测试套餐',
+            'billing_cycle' => 'monthly',
+            'price' => 10,
+            'list_price' => 10,
+            'status' => 'active',
+            'sort' => 10,
+            'published_at' => now(),
+        ]);
+
+        $subscription = SiteSubscription::query()->create([
+            'merchant_id' => $merchantId,
+            'plan_id' => $plan->id,
+            'status' => 'active',
+            'source' => 'manual',
+            'subscription_no' => 'SS_LEN_CFG_0001',
+            'plan_name' => $plan->name,
+            'billing_cycle' => 'monthly',
+            'period_months' => 1,
+            'amount' => 10,
+            'starts_at' => now(),
+            'ends_at' => now()->addMonth(),
+            'meta' => [],
+        ]);
+
+        // 注意：失败原因 Top3 来自关联平台订单的 meta 聚合，不读 subscription.meta
+        \App\Models\PlatformOrder::query()->create([
+            'merchant_id' => $merchantId,
+            'plan_id' => $plan->id,
+            'site_subscription_id' => $subscription->id,
+            'created_by_admin_id' => $platformAdminId ?: null,
+            'order_no' => 'PO_SUB_FAIL_REASON_LEN5_0001',
+            'order_type' => 'renewal',
+            'status' => 'pending',
+            'payment_status' => 'paid',
+            'payable_amount' => 10,
+            'paid_amount' => 10,
+            'placed_at' => now(),
+            'meta' => [
+                'subscription_activation_error' => ['message' => '12345'],
+                'batch_mark_paid_and_activate_error' => ['message' => '12345'],
+            ],
+        ]);
+
+        \App\Models\PlatformOrder::query()->create([
+            'merchant_id' => $merchantId,
+            'plan_id' => $plan->id,
+            'site_subscription_id' => $subscription->id,
+            'created_by_admin_id' => $platformAdminId ?: null,
+            'order_no' => 'PO_SUB_FAIL_REASON_LEN6_0001',
+            'order_type' => 'renewal',
+            'status' => 'pending',
+            'payment_status' => 'paid',
+            'payable_amount' => 10,
+            'paid_amount' => 10,
+            'placed_at' => now(),
+            'meta' => [
+                'subscription_activation_error' => ['message' => '123456'],
+                'batch_mark_paid_and_activate_error' => ['message' => '123456'],
+            ],
+        ]);
+
+        $res = $this->get('/admin/site-subscriptions/' . $subscription->id);
+        $res->assertOk();
+
+        // len=5 应生成链接
+        $res->assertSee('bmpa_error_keyword=12345', false);
+        $res->assertSee('sync_error_keyword=12345', false);
+
+        // len=6 不应生成链接（页面仍会展示 reason 文本）
+        $res->assertDontSee('bmpa_error_keyword=123456', false);
+        $res->assertDontSee('sync_error_keyword=123456', false);
+
+        // 且会出现“原因过长”提示
+        $res->assertSee('原因过长', false);
+    }
+}