The invention relates to a mobile mechanism of a high-rise building wall surface cleaning robot, comprising two fixing support seats and a flexible cable rail used for connecting with the two fixing support seats. A motor reducer component is installed on a horizontal mobile module, and a travelling wheel is connected to an output shaft of the motor reducer component and is installed on the flexible cable rail; two same sets of hoisting systems are arranged in a bilateral symmetry mode, a winding motor is installed on a vertical mobile module, one end of a flexible cable is fixed on a drum, and the other end is fixed on the horizontal mobile module; and a cleaning and adsorption module is fixed below the vertical mobile module. The invention has large motion space, can be installed based on the size of a building to obtain larger motion space, is installed on the outer wall of the building through a horizontal mobile system and a vertical mobile system, can not have the phenomenon that a cleaning mechanism accidentally falls off, can be adapted to various wall surface environments, has wider application range, can change the position and the mobile speed, adopts horizontal and vertical motion decoupling control and has easy realization of a control algorithm.