Abstract: Design parameters of multirow different-shaped spiral groove seeder unit，which was the core component of the small quantity precision seeder，were determinated.Kinematic and dynamic analysis of the small grain seed′s motion state，force，motion parameters were conducted in the entire metering process charge area，protection areas and drop area.Multirow different-shaped spiral groove and geometric parameters of seeding round were selected，and upright form of it was analyzed comparatively.Optimized design parameters of metering wheel under normal seeding speed were obtained.It provides a basis for design of small quantity precision seeder.