Air return device for clean room

The utility model relates to the technical field of clean rooms, and discloses an air return device for a clean room, which comprises a shell, a mounting frame is fixedly connected to the outer side of the end face of one side of the shell, a plurality of lily leaves are arranged on the side, away from the mounting frame, of the shell, and an adjusting knob is arranged at one end of the middle of the end face of one side of the shell. A sliding groove is formed in the middle of the end face of one side of the shell, a filtering plate is slidably connected to the inner wall of the sliding groove, and a servo motor is arranged on the end face of one side of the shell. The servo motor is arranged on the end face of one side of the shell, the output end of the servo motor extends into the shell and is fixedly connected with the screw rod, the screw rod rotates to drive the transmission block to move left and right, the brush rod at the front end of the transmission block sweeps the filter plate, attachments on th