Abstract: In order to ensure the toxic or harmful gases can be effective drainage to return air lane, this paper adopts the method of numerical simulation and uses Pyrosim simulation software to establish the actual size model of the transportation roadway, and to simulate and analyze the spread of toxic and harmful gases in the roadway when a fire occurred. The results show that when CO diffused to the leeward side, it was first detected at the height of 3.1-3.3 m. Based on this characteristic, the control sensor in the drainage system was placed at the height of the transportation lane about 3.3 m, and the detection effect was the best when the sensor was 15 cm below the vault. The core strategy of sensor control is designed for the drainage system. The PLC control device is installed in the return air diversion lane. The double CO and double smoke sensors are used to control the aluminum alloy rolling shutter air window for air flow automatic regulation. In order to ensure that the fire smoke flow is completely drained, a two-way wind speed sensor is set to assist the control, and the remote monitoring system through the wind window is used to realize the real-time monitoring and control of the workers on the shaft. Through field application, a good drainage effect has been achieved.