The Ball mill can be divided into lattice type and overflow type according to different beneficiation methods, and this machine is two lattice-type ball mill. The materials from the feeding fittings enter evenly to the first bin of the milling machine via the feeding hollow axis when it works. There is a ladder-like or ripple-like scaleboard in the first bin, and different specification steel balls are installed in the bin. When the cylinder rotates and produces centrifugal force, the force carries steel balls into a certain height and then makes them fall to strike and grind the materials. After coarse grinding in the first bin, the material then enters into the second bin via a single layer partition board. There is a scaleboard and steel boards in the second bin, so the materials are further ground. In the end, the powder is discharged by output material board.