Abstract: In existing tobacco thresher,the projector with a picker roller has the disadvantage of higher tobacco degradation,and the high speed projector has the problem of serious tobacco return,therefore a pneumatic projector was designed,which was composed of a high pressure fan,a branching pipe,a metal hose,an air chamber and a regulating device.The threshed tobacco was carried by the high speed air stream formed by air chamber and projected into the pneumatic separator chamber.Comparing with mechanical projector,the pneumatic projector effectively reduced tobacco breakage,the content of large and middle size strips increased by about 2.7 percentage points,while fines content and the content of stem in strips decreased by 0.8 and 0.1 percentage points,respectively.The projecting angle of pneumatic projector was adjustable dependent on the tobacco being processed to achieve higher efficiency.