Underwater cleaning machine

The utility model provides an underwater cleaning machine. The underwater cleaning machine comprises a shell, a filtering unit, a walking unit, a control unit and a buoyancy adjusting unit. The filtering unit is arranged in the shell; the buoyancy adjusting unit is connected with the shell; the control unit is connected with the shell; under the driving of the control unit, the walking unit moves or stays still on a surface to be cleaned; the control unit is electrically connected with the buoyancy adjusting unit so that the underwater cleaning machine can move back and forth between the underwater surface to be cleaned and the water surface. The buoyancy adjusting unit is located at the non-front end of the shell, and one end of the underwater cleaning machine in the advancing direction is the front end of the shell. The machine floats out of the water surface when needing to be cleaned or maintained, the machine does not need to be manually found or lifted out of the water surface, and manual labor is reduc