A ball mill is a horizontal cylindrical rotating device driven by external gears, two hoppers, and a grid ball mill. The material is uniformly fed into the first grinder through the hollow shaft of the feeding device. The bunker has a stepped or corrugated bunker with steel balls of different characteristics. The rotation of the cylinder generates centrifugal force, which lifts the steel ball to a certain height. After falling, it will generate strong impact and material wear. Once the material reaches a worn state in the first warehouse, it will enter the second warehouse through a single-layer partition. The warehouse is equipped with flat bottomed seats and steel balls for further grinding of materials. The powder is discharged through the discharge net to complete the grinding operation.