Aiming at the design requirements on the main equipments of the forageseed processing line—not only work continuously on set, but also work independently—the processing line was designed. The processing line adapted the style of host plane layout and hopper feeding at different sites, and combined series conveying material by head-shaped lifter. The structure of the tee with door, pipe connection clip and dust removal pipe air separation unit was designed. Taken the Elymus nutans Griseb with purity 85%~88% as processing object, the experiment was finished. The results showed that the productivity was no less than 800kg/h, the purity was no less than 97%, the percentage of chosen seed was no less than 95%, the Kilowatt hour productivity was no less than 25kg/(kW·h), the effective use degree was no less than 95%, and the dust concentration was no less than 0.3mg/m3.