Building external window cleaning robot

The utility model discloses a building external window cleaning robot, which relates to the field of building facility cleaning, and comprises a first track and a cleaning robot, the first track is fixedly arranged on the upper edge of an external window, and the first track is connected with the cleaning robot through a lifting part; the lifting part comprises a first sliding block, a telescopic piece, a connecting piece and a second rail which are fixedly connected in sequence from top to bottom; the first sliding block can move back and forth on the first track, the cleaning robot comprises a robot body, a second sliding block is arranged at the top end of the robot body, the second sliding block runs in the second track, the robot body comprises a lateral cleaning part, and the lateral cleaning part is used for cleaning the four corners of the outer window. Four corners of the building external window can be cleaned through the lateral cleaning part, meanwhile, the cleaning robot operates through the firs