Belt conveyor is one of the key transportation equipment in coal production. Due to the phenomenon of material adhering to belt in coal transportation operation, belt deviation and slippage are caused. In order to improve the transportation efficiency of belt conveyor, taking DTJ-120/2x250 belt conveyor in Xinjing Coal Mine as the research object, the self-cleaning coal piling device was designed according to the problems existing in the current coal cleaning device. Practice shows that the designed coal pile cleaning device effectively improves the cleaning efficiency, reduces the labor intensity of the staff, has good cleaning effect, and ensures the operation reliability of the belt conveyor.