Abstract: The charging of monorail hoist is prone to causing carbon monoxide to exceed the limit, due to power-off caused by exceeding the limit, the existing mine safety monitoring system will trigger multi-sensor alarms in the return air flow, as well as stop production and personnel evacuation. Therefore, it is necessary to carry out research on risk prevention technology for CO sensor early warning power-off function. By adding a power-off function for carbon monoxide sensors before exceeding the limit in the coal mine safety monitoring system, and relying on software development and safety monitoring system, monitoring substation, sensor, power-off controller, and sound and light alarm, a real-time monitoring and prevention and control system for carbon monoxide concentration in the downhole monorail hoist charging chamber is constructed. The application indicates that when the air volume of the monorail hoist charging chamber is 100 m³/min, the sensor indicating value doesn’t reach the 24 × 10⁻⁶ alarm value after early warning power-off; When the air volume of return air flow is 300 m³/min, the increase of indicating value is less than 6 × 10⁻⁶. This technology can achieve real-time monitoring and rapid response, effectively reduce the disaster risks of toxic and harmful gases, fire disasters and others, which is of great significance for the management of mine fire prevention and extinguishing.