The invention relates to a coal return protection device of a belt conveyor. The coal return protection device comprises a coal baffle plate, a coal return protection handle and a detection action switch, wherein the coal baffle plate is fixed on a tail rack at the front end of a tail roller of the belt conveyor, a bottom end is kept a certain height above a bottom belt, the coal return protection handle is arranged on the tail rack between the tail roller and the coal baffle plate, and one side, close to the coal baffle plate, of the coal return protection handle is electrically connected with the detection action switch. After the coal return protection device disclosed by the invention is installed, phenomena such as coal return or belt scratch caused by other hard objects are prevented, time affected by electromechanical accidents is shortened, and electromechanical safety is further improved.