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Discrete element method was used to analyze the influence of working parameters on supplying seeds performance of magnetic precision cylinder seeder. Tomato powder coated seed was taken as the object of study, and then the seed and seeder simulation model was established. The mechanical interaction forces, both between seed and seeder and among the seeds were modeled by Hertz-Mindlin method(no slip). The effects of vibration frequency and amplitude on the seeds movement rule and the supplying performance were analyzed. The simulation results showed that when the vibration frequency was 40Hz and the vibration amplitude was 0.5mm or 0.75mm, the seeds accumulated a stable height and the ideal seeds supplying performance could be received, which was beneficial to improve suction precision. In order to verify the reliability of the simulation model, high-speed photography technology was used to record the supplying process with the seed box vibration frequency of 40Hz and vibration amplitude of 0.75mm, and the supplying results were consistent with the simulation results. Experiments were carried out on magnetic precision cylinder-seeder and the results showed that the single grain rate was greater than 92% and leak seeding rate was less than 3% with the seed box vibration frequency of 40Hz, vibration amplitude of 0.5mm and 0.75mm. The single grain rate was lower than 80% with vibration frequency of 20Hz and 60Hz, with different amplitudes.