diff --git a/backend/internal/service/gateway_service.go b/backend/internal/service/gateway_service.go
index 0fe2545ec0..f6c993a89c 100644
--- a/backend/internal/service/gateway_service.go
+++ b/backend/internal/service/gateway_service.go
@@ -3424,6 +3424,10 @@ func (s *GatewayService) isModelSupportedByAccount(account *Account, requestedMo
 	if account.Platform == PlatformSora {
 		return s.isSoraModelSupportedByAccount(account, requestedModel)
 	}
+	// OpenAI 透传模式：仅替换认证，允许所有模型
+	if account.Platform == PlatformOpenAI && account.IsOpenAIPassthroughEnabled() {
+		return true
+	}
 	// OAuth/SetupToken 账号使用 Anthropic 标准映射（短ID → 长ID）
 	if account.Platform == PlatformAnthropic && account.Type != AccountTypeAPIKey {
 		requestedModel = claude.NormalizeModelID(requestedModel)