Abstract: The ball-mills is one of the key equipments of ore dressing plants.Its energy consumption(including the electricity consumption and the cost of the materials) makes up 30%～60% of the consumption of the whole factory usually.And its work-state is the key factor which effect various economic and technologic targets directly,such as the production ability and rate.In the last 20 years,great progress has been made through the research of the ball-mills,and some new development trends have appeared.