diff --git a/plugins/services/mongodb.go b/plugins/services/mongodb.go
index 63d133e..8b43d4d 100644
--- a/plugins/services/mongodb.go
+++ b/plugins/services/mongodb.go
@@ -39,15 +39,15 @@ func (p *MongoDBPlugin) Scan(ctx context.Context, info *common.HostInfo) *ScanRe
 		}
 	}
 
-	for _, cred := range credentials {
-		if p.testCredential(ctx, info, cred) {
-			common.LogSuccess(fmt.Sprintf("MongoDB %s %s:%s", target, cred.Username, cred.Password))
-			return &ScanResult{
-				Success:  true,
-				Service:  "mongodb",
-				Username: cred.Username,
-				Password: cred.Password,
-			}
+	// 优化：只测试一次连接，检查是否允许无认证访问
+	if p.testUnauthenticatedAccess(ctx, info) {
+		common.LogSuccess(fmt.Sprintf("MongoDB %s 无认证访问", target))
+		return &ScanResult{
+			Success:  true,
+			Service:  "mongodb",
+			Username: "",
+			Password: "",
+			Banner:   "无认证访问",
 		}
 	}
 
@@ -61,6 +61,11 @@ func (p *MongoDBPlugin) Scan(ctx context.Context, info *common.HostInfo) *ScanRe
 
 
 func (p *MongoDBPlugin) testCredential(ctx context.Context, info *common.HostInfo, cred Credential) bool {
+	// 这个方法现在不使用，保留以防向后兼容
+	return p.testUnauthenticatedAccess(ctx, info)
+}
+
+func (p *MongoDBPlugin) testUnauthenticatedAccess(ctx context.Context, info *common.HostInfo) bool {
 	target := fmt.Sprintf("%s:%s", info.Host, info.Ports)
 	timeout := time.Duration(common.Timeout) * time.Second
 
@@ -147,6 +152,8 @@ func (p *MongoDBPlugin) identifyService(ctx context.Context, info *common.HostIn
 	defer conn.Close()
 
 	conn.SetDeadline(time.Now().Add(timeout))
+	
+	// 简化识别逻辑：先尝试基础查询，失败则使用端口推断
 	if p.testBasicQuery(conn) {
 		banner := "MongoDB"
 		common.LogSuccess(fmt.Sprintf("MongoDB %s %s", target, banner))
@@ -156,11 +163,22 @@ func (p *MongoDBPlugin) identifyService(ctx context.Context, info *common.HostIn
 			Banner:  banner,
 		}
 	}
+	
+	// 如果查询失败但能建立TCP连接，且是MongoDB默认端口，推断为MongoDB
+	if info.Ports == "27017" || info.Ports == "27018" || info.Ports == "27019" {
+		banner := "MongoDB (端口推断)"
+		common.LogSuccess(fmt.Sprintf("MongoDB %s %s", target, banner))
+		return &ScanResult{
+			Success: true,
+			Service: "mongodb", 
+			Banner:  banner,
+		}
+	}
 
 	return &ScanResult{
 		Success: false,
 		Service: "mongodb",
-		Error:   fmt.Errorf("无法识别为MongoDB服务"),
+		Error:   fmt.Errorf("无法识别为MongoDB服务: 连接成功但协议查询失败"),
 	}
 }