The grinding system contains two kinds of technology forms, open circuit and close circuit used in the aluminum carbon industry. At present it is in perfect operation and has produced so much favorable comment. In the grinding system , improvements were made to the grinding equipment-ball mill, making it more scientific and reasonable, more reliable and safer, less noise and longer service time. As a result, the continuous operation ratio has been greatly improved. What needs to be pointed out is the efficient rotor classifier equipped in this grinding system. It selects advanced wear resistant material to reduce the rate of wear while working. The classification force of this system can be adjusted, to meet the demands of the finished product. The efficiency of classification can be over 85%, and the evenness index of finished product is between 1.2-1.5.