The invention belongs to the technical field of automobile part processing, and particularly discloses an automobile part polishing device. The automobile part polishing device comprises a polishing unit, a conveying unit and a pushing unit; the material pushing unit comprises a placing table, a cylindrical cam, an annular cylinder and a communicating column, wherein the annular cylinder is located above the placing table, and a clamping groove is formed in the curved contour surface of the cylindrical cam; a first plunger is slidably connected to one side of the communicating column, a secondplunger is slidably connected to the other side of the communicating column, and a tension spring is connected between the second plunger and the communicating column; a communicating pipe is arranged on the communicating column, a piston is slidably connected in the communicating pipe, and a connecting rod is fixed to the piston; the polishing unit comprises a fixed cylinder and a baffle; a polishing block capable of extending out of the lower part of the fixed cylinder is slidably connected in the fixed cylinder, and sandpaper is arranged on the lower surface of the polishing block; and thecommunicating column is connected with a connecting pipe, and the fixed cylinder communicates with the discharge end of the connecting pipe. By using automobile part polishing device, the two opposite sides of a part can be polished at the same time, and the efficiency is improved.