The invention discloses an intelligent curtain wall cleaning system, which comprises a mounting frame, a cleaning machine, a driving device and a controller, wherein the mounting frame is fixedly mounted on the outer periphery of a curtain wall, specifically, the mounting position can be arranged at four corners of the outer periphery of the curtain wall; the cleaning machine is mounted on the mounting frame in a movable manner; the cleaning machine has horizontal and vertical movable strokes; the driving device is connected with the cleaning machine in a driving manner to drive the cleaning machine to move on the mounting frame; and the controller is electrically connected with the driving device, and controls the horizontal and vertical movements of the cleaning machine by controlling the driving device. As the cleaning machine has horizontal and vertical movement strokes, the cleaning machine can clean the building curtain wall in a large range, especially replacing manual cleaningin high-altitude operation or bad weather, and thus casualties can be avoided, and the appearance of the building curtain wall is maintained all the time; and meanwhile, through intelligent control ofthe controller, the intelligent cleaning of the building curtain wall can be realized, so that the cleaning efficiency is improved, and the labor cost is saved.