The invention discloses an automatic ball sorting machine. The automatic ball sorting machine comprises a machine frame, a charging barrel, a ball conveying pipe, a sorting device, a first material falling device and a second material falling device. The sorting device comprises a sensor, a baffle, an arc rack, a first gear and a first motor. An output shaft of the first motor drives the baffle to swing through engagement of the first gear and the arc rack. The lower end of the baffle is connected with the sensor. The distance between the sensing end and the bottom of the ball conveying pipe is equal to the diameter of balls. The first material falling device comprises a material falling plate, a first material falling pipeline, an oblique pulling rod, a sliding block, a second gear and a second motor. An output shaft of the second motor drives the material falling plate to overturn through engagement of the second gear and the rack and cooperation of the sliding block and the oblique pulling rod. By adopting the structure, manual sorting is replaced, the production efficiency is greatly improved, the sorting precision is higher, and operation is more convenient.