The invention provides a stair sweeping robot capable of moving based on Mecanum wheels. The robot is mainly composed of a driving device, lifting devices, a whole support, a sweeping device, a distance sensor and an upper computer system, wherein the lifting device comprises a lifting motor, a lifting motor fixing frame, a coupler, a lead screw, a lifting supporting frame and a bearing, the driving device drives the four Mecanum wheels through four motors independently, the four lifting devices are installed in four lifting guide wheel gaps respectively, the sweeping device is installed on aMecanum wheel supporting frame, and the driving device, the lifting devices, the sweeping device and the distance sensor are all connected to the upper computer system. Flexible movements including advancing, retreating, transverse moving, rotating and other movements in any direction can be completed when the Mecanum wheels do not rotate; through the distance sensor, the environment is sensed, the lifting height and the advancing distance are adjusted, and the sweeping work of stairs of various different sizes can be completed; the robot can also be used for sweeping the ordinary ground.