Installed on the vehicle, emergency alarm button Connecting with the Alarm input port of the MDVR for panic alarm. Once an abnormal situation occurs, the passenger or the driver only needs to trigger the switch slightly,then the MDVR system will be triggered, and the monitoring display screen in the control center will automatically jump out of the corresponding vehicle video and alarm sound to notice the controllor, the video data will be automatically and automatically stored as alarm video data information. Security personnel in the control center will see the alarm information as soon as possible, and will ensure the safety of the driver and passengers as soon as possible, which will help the police to conduct investigations, analysis, evidence collection and handling the cause of the accident.