Abstract: The article analyzes the problems in current mechanical air door interlocking device in mine, and makes some improvements for the existing problems. The air door interlocking device is changed to air door locking device. The structure, working principle, precautions and the advantages of the air door locking device are briefly introduced. The application of the air door locking device completely eliminates the phenomenon of the two air doors opening at the same time, improves the stability of ventilation system, and ensures the safety production of mine.