As selecting process of the inferior-quality product from processed product does not only occupy too large field, but also requires high labor intensity, and the staff usually have blurred vision after selecting for a long time, the specially developed equipment, overcoming the above disadvantages, can bear one ton per bunk, with a coverage of about 2 square meters. The operator can stand or sit in front of the bunk for selection. The dust in the ball product will be automatically removed when passing over the screen in the transportation from the ball to the operating platform.