With the development of powder metallurgy industry, the fine-metal-powder classification becomes one of the vital techniques in powder technology. A pneumatic classifier without screen and mechanical moving parts is designed and developed. Three samples are used in the pneumatic classification experiments and the separation sizes are 45μm， 45μm and 30μm, respectively. The oversize ratio in fine powder can be reduced to less than 5% and the undersize ratio in coarse powder less than 15% when the air flow is suitable, simultaneously. The classification effect is satisfactory.