The GQB-S400-M mobile regional gas detection and alarm instrument integrates pump suction gas detection, battery power supply, and video monitoring. It can conduct real-time detection of hazardous gases in confined spaces, remotely monitor and store operation videos, and supports 4G network communication. It can upload real-time gas concentrations at the operation site, video operation images, and alarm data to the PC terminal at the monitoring center and remote mobile phones. Through the monitoring software on the PC and mobile phones, the concentration of hazardous gases in the confined space can be known, and the video operation situation in the confined space can be mastered. Once the concentration of hazardous gases detected reaches the preset alarm value, the mobile regional gas detection and alarm instrument will give sound and light alarms and synchronously warn the supervisors wearing interconnected portable gas detection and early warning instruments within 50-100 meters at the site. Through this function, the expansion of accidents caused by blind rescue can be effectively avoided.