The invention relates to an up feeding and down feeding double-grading type high-efficient powder concentrator, which mainly consists of an upper case, a middle case, a lower case, a transmission support frame, a baiting collection pipe, a grading rotor, a main shaft sleeve, a main shaft, a material spreading disc, a grading blade, a speed reducer, an electric motor and the like, wherein the speed reducer and the electric motor are arranged on the transmission support frame. The invention is characterized in that the upper part of the middle case is connected with the upper case, the center position of the upper case is connected with an air outlet large bent pipe, the top of the upper case is connected with a material inlet pipe, the lower part of the middle case is connected with the lower case, the lower case is provided with a material and gas inlet vertical pipe, and the material and gas inlet vertical pipe is provided with a regulation air valve. The upper case is formed by a plane cross-section hollow cone and a hollow cylinder through up and down butt joint split welding, the middle case is a reverse plane cross-section hollow cone, and the lower case is formed by an inclined cross-section hollow cylinder and an eccentric inclined cylindrical baiting tube body through connection. The invention has the advantages o large material processing capability, good dispersivity, high powder concentration efficiency, low air resistance and the like.