diff --git a/backend/internal/service/account_test_service.go b/backend/internal/service/account_test_service.go
index 99046e30..9557e175 100644
--- a/backend/internal/service/account_test_service.go
+++ b/backend/internal/service/account_test_service.go
@@ -180,7 +180,7 @@ func (s *AccountTestService) TestAccountConnection(c *gin.Context, accountID int
 	}
 
 	if account.Platform == PlatformAntigravity {
-		return s.testAntigravityAccountConnection(c, account, modelID)
+		return s.routeAntigravityTest(c, account, modelID)
 	}
 
 	if account.Platform == PlatformSora {
@@ -1177,6 +1177,18 @@ func truncateSoraErrorBody(body []byte, max int) string {
 	return soraerror.TruncateBody(body, max)
 }
 
+// routeAntigravityTest 路由 Antigravity 账号的测试请求。
+// APIKey 类型走原生协议（与 gateway_handler 路由一致），OAuth/Upstream 走 CRS 中转。
+func (s *AccountTestService) routeAntigravityTest(c *gin.Context, account *Account, modelID string) error {
+	if account.Type == AccountTypeAPIKey {
+		if strings.HasPrefix(modelID, "gemini-") {
+			return s.testGeminiAccountConnection(c, account, modelID)
+		}
+		return s.testClaudeAccountConnection(c, account, modelID)
+	}
+	return s.testAntigravityAccountConnection(c, account, modelID)
+}
+
 // testAntigravityAccountConnection tests an Antigravity account's connection
 // 支持 Claude 和 Gemini 两种协议，使用非流式请求
 func (s *AccountTestService) testAntigravityAccountConnection(c *gin.Context, account *Account, modelID string) error {