The embodiment of the invention provides a robot charging method and a robot charging device. The method comprises the steps of detecting a path pilot signal emitted by a charging pile and a real-time distance between a robot and the charging pile, if the electric quantity of the charging pile is lower than a preset threshold; and determining a moving direction according to the path pilot signal, and determining a moving speed according to the real-time distance, and controlling the robot to move to the charging pile at the moving speed along the moving direction. The moving speed of the robot is controlled during a process that the robot moves to the charging pile according to the distance between the robot and the charging pile, so that the defect that collision or low time efficiency may be caused by too fast or too slow moving speed can be overcome. Then a charging request including the electric quantity is sent to the charging pile in response to a butt-joint indication signal, so that the situation that the robot triggers a charging requirement is determined if the charging pile receives the charging request within preset time, the charging pile is triggered to charge the robot, and the security problem caused by the condition that the charging pile is mistakenly triggered for charging is solved.