Abstract: Aiming at the problems of low target recognition accuracy, poor response sensitivity and poor opening and closing of the current coal mine air door control system, the automatic locking control and monitoring technology of the air door is studied, and an intelligent locking control system of the underground air door based on PLC is designed. The system integrates multi-sensor information, which can realize the accurate identification of tramcars, pedestrians and other traffic targets, and the real-time acquisition and analysis of environmental parameters such as temperature, smoke, methane and so on. The experimental results show that the recognition accuracy of the system for different traffic targets can reach more than 97.6%, the measurement errors of environmental parameters are less than ± 3.6%, and the success rate of double door interlock implementation can reach 100%, effectively enhancing the reliability and intelligent level of air door control.