When the conveyor belt is torn, punctured, damaged or sharp objects protrude, the tear switch can send an alarm signal to the monitor or turn off the conveyor. Tear switches are installed in pairs on the conveyor belt and connected by two sections of aircraft cables with B-type sheath. One end of the aircraft cable is fixed on the support frame; The other end is connected to the pull ring of the tear switch, and two pieces of aircraft cable form a monitoring surface under the conveyor belt. When an object or torn tape is hung and swept down to the aircraft cable, the aircraft cable pulls the pull ring of the tear switch to make it act, and the tear switch sends out an alarm signal or a stop signal.