After the material enters the classifier through the feed inlet of the feeding mechanism, it is evenly distributed by the distribution plate on the vertical classifier wheel and thrown into the baffle ring, falling into the classifier area. The graded air enters the spiral air cavity and flows into the classifying wheel in the centripetal direction through the guide disc blade. The fine powder meeting the particle size requirements is separated out under the gravity action of the classifying area. The fine powder flows with the graded air at high speed and enters the fine powder collecting system, and then is separated from the graded air. The coarse powder falls into the lower part of the classifier and is discharged by the electric discharge valve with air seal.