Compressed air is accelerated into supersonic air flow by the nozzle and then injected into the crushing zone, so that the material is fluidized (air flow expansion is fluidized bed suspension boiling and collision with each other), so each particle has the same state of motion. In the crushing zone, the accelerated particles collide with each other at the intersection of each nozzle, and the crushed material is transported to the classification zone by the rising air flow, and the fine powder that reaches the particle size is screened by the high-speed rotating classification wheel, and the coarse powder that does not meet the particle size requirement is returned to the crushing zone to continue crushing. Qualified fine powder enters the cyclone trap with the airflow to be collected, and the dust-containing gas is filtered and purified by the dust collector and discharged into the atmosphere.