To provide a coaxial multi-class type classifier for ultrafine particulate powder.

The coaxial multi-class type classifier for ultrafine particulate powder includes a separation cylinder and an air extraction tube that are coaxially disposed. The separation cylinder is provided with a hollow body, to the both ends of which relatively-arranged first diameter reduction hole and second diameter reduction hole are connected respectively. The air extraction tube is provided with a plurality of hollow tubes having different tube diameters, wherein one end is arranged coaxially with the direction of the first diameter reduction hole and the other end is extended from the second diameter reduction hole to the outside of the separation cylinder and successively connected to the air extraction device. The present invention by the arrangement of the foregoing constituents mainly utilizes the principle of equi-action force extraction, separately collecting ultrafine particulate powder of different particle sizes correspondingly to the hollow tubes having different tube diameters of the air extraction tube. Thus, the volume of the classifier is reduced, with the manufacturing cost curtailed, providing a merit and effect of performing multi-class type recovery.