Abstract: In this paper, research results of peeling technology for some small diameter cereals were presented. The study found out some inherent laws between the peeling parameters, such as the helix angle (β), gears interval (t), rotating speed (ω) and the gears gap (δ), and the peeling effect with a mathematic model after taking many orthogonal multinomial regressive tests with multi-factors and multi-levels. The main test material is rapeseed, the typical oil seeds which is widely planted in the south China. This research result laid a reference of optimizing design of apparatus for small diameter plant seeds peeling.