In order to improve the sowing performance of vibrating small-amount rice sowing device, theoretical analysis and experimental research on the mechanism of the quantitative-seeds feeding mechanism and the vibration uniform-seeds mechanism were carried out respectively. Discrete elemental software EDEM was used to simulate the feeding process of quantitative-seeds feeding mechanism with or without vibration. Through the comparative analysis of the simulation process of the quantitative-seeds feeding mechanism, the periodic small amplitude vibrations of seed box vibrating plate could alleviate the rice seeds funnel flow and promote the diffusion flow, meanwhile made the distribution state of the seeds in the seed roller fluffier. The simulation results of the quantitative-seeds feeding test showed that the vibrating effect of the seed box vibrating plate could increase the seed frequency, and realize the quantitative and stable seeds feeding performance. The simulation experiment of seeding performance of nine kinds of grooved plates was carried out to study the effect of different kinds of grooved plates on the seeds flow velocity and sowing effect. The simulation results of sowing performance experiment showed that with the increase of the grooved plate’s angle, the flow velocity of seeds on the grooved plate was gradually decreased and tended to be stable. The V-90°, V-105°, V-120° and U1-shaped grooved plates were optimized to provide reference for the vibration uniform-seeds mechanism optimization test, and reduced the number of subsequent tests. Through the sowing performance tests, it was obtained that the best sowing performance was using the V-120° grooved, and the qualified index was 93.91% while hole index was 0.94% when sowing hybrid rice with 0.26MPa air pressure. The qualified index was 96.10% and the hole index was 0 when sowing conventional rice with 0.28MPa. The research provided a research basis for the research and development of rice precision sowing device.