The invention discloses a mechanical cleaning device for a glass reaction kettle. The mechanical cleaning device comprises a transverse plate, supporting legs, rollers and a driving motor, wherein central through holes are formed in the center of the transverse plate, threaded sleeves are arranged above the central through holes, and the threaded sleeves are in threaded connection with sleeve columns; and the sleeve columns are provided with external threads matched with the threaded sleeves, and the cleaning device is arranged below the sleeve columns. According to the cleaning device, the sleeve columns containing scrubbing heads and scrubbing plates are arranged, the cleaning device is conveyed into a kettle body from kettle openings, and the cleaning device is unfolded through the rotating handle; the cleaning device can be adapted to scrubbing operation of glass reaction kettles of different specifications; and the device is provided with the driving motor and a forward and reverse rotation transmission mechanism, the cleaning device is driven to move up and down, and compared with the manual work, the scrubbing efficiency and the scrubbing effect are greatly improved.