The invention relates to a classification type efficient ultrafine grinder comprising a rack (1), wherein a feeding chamber (18), a grinding chamber (14) and a discharging chamber (15) are arranged on the rack (1); a grading chamber (23) is arranged at the top of the rack (1) and is located above the discharging chamber (15); the discharging chamber (15) is connected with the grading chamber (23) through a conveying pipeline I (33); a coarse material discharging opening (34) is formed in the bottom of the grading chamber (23); a coarse material air seal machine (22) is arranged below the coarse material discharging opening (34) in a connected manner; and the lower end of the coarse material air seal machine (22) is connected with a feeding opening (21) of the grinding chamber (14). According to the classification type efficient ultrafine grinder provided by the invention, a material enters the grinding chamber for three grinding processes; the grinded material is fed into the grading chamber; the material with a required fineness enters a cyclone discharging process; and a coarse material falls back to the grinding chamber for secondary grinding, so that the heat of a machine cavity is effectively reduced, and the production efficiency is improved.