The invention discloses an environment-friendly energy-saving plate polishing device which comprises a device body. A connection rod is fixedly installed on one side of the device body, a rotating shaft groove is formed in the bottom of the connection rod, a rotating shaft is rotationally installed in the rotating shaft groove, the bottom end of the rotating shaft is extended out of the rotating shaft groove, the bottom of the rotating shaft is provided with a connection rod groove, the connection rod is installed in the connection rod groove in a sliding mode, the bottom end of the connectionrod is extended out of the connection rod groove, and a polishing disc is fixedly installed at the bottom end of the connection rod. The inner walls on the two sides of the connection rod groove areprovided with sliding rod through holes correspondingly. Sliding rods are installed in the sliding rod through holes in a sliding mode. One end of each sliding rod is extended out of the correspondingsliding rod through hole. The inner walls of the two sides of the connection rod are provided with clamping block grooves located in the connection rod groove, and clamping blocks are installed in the clamping block grooves in a sliding mode. The structure is simple, use is convenient, installation of the polishing disc is more stable, dismounting and mounting are convenient, operation is easy, time is saved, and working efficiency is improved.