The present invention relates to a monitoring device of face identification and alarm based on a machine room. The device comprises a high-speed monitoring camera and a virtual warning line arranged in the machine room, the high-speed monitoring camera is provided with a camera abnormity monitor and a snapshot mechanism, a virtual warning line is provided with an infrared sensor, the infrared sensor is connected with the snapshot mechanism of the monitoring camera, a face identification device, a vision camera and an alarm unit are arranged at the access of the machine room, the information of the face identification device, the vision camera and the alarm unit are transmitted to the monitoring center of the machine room in real time; the face identification device comprises a face image collection module, a face image regulation amplification module, a night infrared detection module, a face location module and a face identification processor; the vision camera comprises an image processor, a light source and an optical lens; and the monitoring center is connected with a calling center personnel management base. The safety of the machine room is ensured.