The invention discloses a thickness detection device used for brake clutch plate production. The thickness detection device comprises a detection bench, an assembly plate, a conveyor belt, a lifting platform, an infrared range finder and an infrared sensor. The detection bench is L-shaped, the lower side of the top is placed in front, the assembly plate is vertically welded on the front side of the top, and the conveyor belt is fastened between the higher side of the top and the assembly plate. The infrared sensor is a cuboid, and is locked on the right side of the top of the assembly plate, and penetrates through the assembly plate and is electrically connected with the detection bench. The lifting platform is a cuboid. When the thickness detection device is used, by means of mechanisms of a push rod, an electromagnet, a gear, a toothed bar and a screw which are arranged on the thickness detection device after the brake clutch plate is transmitted to a designated position, the thickness detection device automatically stops transmission and automatically lowers a measuring bench, when the measuring bench is lowered to make contact with a measured object, the measuring bench automatically stops lowering by means of an ejecting switch and the like, and can carry out measurement, accurate measurement is guaranteed, the thickness detection device is convenient to use, measurement errors are reduced, and furthermore the safety of subsequent usage can be well guaranteed.