The invention discloses an automatic window wiping robot which comprises a hoisting mechanism and a robot body. The positioning and moving work of the robot body is completed by the hoisting mechanism. The robot body comprises a fixing mechanism and a wiping mechanism. The fixing mechanism is composed of two fixing arms installed on a fixing rod. The wiping mechanism is installed on a lead screw of the fixing rod. The automatic wiping process is achieved for outer surface glass of a high-rise building, high-risk and high-intensity work of manual wiping is avoided, and work efficiency is greatly improved; the robot has high mobility and universality and can be suitable for about 50% of high-rise buildings, and cost is far lower than the cost for reserving rails and manufacturing window wiping machines in the building constructing process.