The electromagnetic lock is based on the principle of electromagnetism. When the current passes through the silicon steel sheet, the electromagnetic lock will generate a strong suction force and tightly attract the iron plate to achieve the effect of locking the door. As long as a small current electromagnetic lock will generate great magnetic force, the access control system that controls the power supply of the electromagnetic lock recognizes that the person is powered off immediately, and the electromagnetic lock can open the door if it loses suction. Because the electromagnetic lock does not have a complicated mechanical structure and the structure of the bolt, it is suitable for the access control of the escape door or fire door.