The invention relates to the technical field of workpiece barrel plating equipment in the electroplating industry and particularly relates to a planetary barrel plating machine. The planetary barrel plating machine comprises a controller, a first bevel gear, an outer cover, a rack, a roller mounting frame, a first bearing support, a transmission shaft, a second bearing support, a planetary roller mechanism, a second bevel gear, a motor and a third bevel gear; the controller is installed in the rack and is used for supplying power to the motor and controlling the speed of the motor; the motor is fixed on the rack, the motor is connected with the first bevel gear, the first bevel gear is engaged with the second bevel gear, and the second bevel gear and the third bevel gear are respectively installed at the upper and lower ends of the transmission shaft; the transmission shaft is installed on the roller mounting frame through the first bearing support and the second bearing support, and the roller mounting frame is fixedly connected with the rack through a screw; the outer cover is fixedly arranged on the rack and covers the controller and the motor; the working efficiency of the planetary barrel plating machine is much higher than that of a common single-roller barrel plating machine, the plated part quality is relatively higher and the electroplating reaction time is shorter.