Concrete wall surface polishing device

The utility model discloses a concrete wall polishing device which comprises a polishing shell and a dust collecting mechanism, a motor is arranged in the polishing shell, an output shaft of the motor is connected with a rotating rod, the right side face of the polishing shell is connected with a polishing disc through a rotating shaft, and the end, away from the polishing disc, of the rotating shaft is connected with a first gear. An outer sleeve is arranged on the right side face of the grinding shell, an inner sleeve is inserted into the outer sleeve, and the dust collection mechanism comprises a dust suction cover, a dust suction pipe, a concentration box, a suction pump, a corrugated pipe and a dust collection water tank. The grinding disc is extruded towards a wall surface through the handle, the inner sleeve is in contact with the wall surface and moves towards the interior of the outer sleeve due to extrusion, and the spring is compressed to generate elastic force until the grinding disc is in contact