The motor drives the reducer to rotate the grinding disc. The material is fed into the center of the grinding disc through the air-locking feeding device, and moves to the edge of the grinding disc under the action of centrifugal force and enters the grinding roller. Under the pressure of the grinding roller, the material is squeezed, ground, sheared and crushed. At the same time, hot air is ejected from the air ring at high speed, blowing up the ground material, blowing the coarse particles back to the re-grinding, and the suspended materials are dried. The fine powder enters the separator for classification with the hot air. The qualified fine powder is discharged with the air flow and collected by the dust collecting equipment. The coarse powder falls back to the grinding disc under the action of the separator and is re-grinded with the new material, completing the grinding operation in a cycle.