The invention relates to a robot automatic hanging system. The robot automatic hanging system comprises a hanging part automatic supply device, a robot, an automatic correction device and a control device. The hanging part automatic supply device comprises a feeding station, a conveying unit, a transfer unit transferring hanging parts from the feeding station to the conveying unit and a hanging station. The conveying unit conveys the hanging parts to the hanging station. The robot takes the hanging parts out from the hanging station through a hanging jig to move towards a hanging plate. The automatic correction device comprises a correction mechanism capable of adjusting hanging buckling portions of the hanging parts to exactly face hanging buckling holes of the hanging plate. The controldevice comprises a processor communicating with a device body and a monitor unit used for monitoring the movement position of the hanging plate, the monitor unit feeds back information to the processor, and the processor issues the command of operation or waiting or hanging or reset to the robot according to the information. According to the robot automatic hanging system, the hanging parts can beautomatically supplied, the positions and angles of the hanging parts can be adjusted, then the hanging parts are extracted by the robot, hanging buckling butt joint is achieved under movement synchronous with the hanging plate, and therefore hanging stability and accuracy are greatly improved.