Abstract: Aiming at the small size, poor fluidity and irregular shape of white radish seeds, the seed suction effect of seed planter is poor, the leakage rate index is high, and the repeat rate index is high, an air suction disc white radish planter is designed. Based on the analysis of the structure and working principle of the planter, the force of adsorbing single seed was designed and calculated, the mechanical model was established, and the minimum adsorption negative pressure of single seed was obtained. Then through the rotation ratio of the number of chains, the relationship between the ground wheel of the planter and the number of seeding device was determined. Through the single factor test of DEM-CFD coupling simulation of seed suction process, the optimal range of key structural parameters of seed discharge device in seed seeder was calculated and determined: the speed of seed discharge disc in seed discharge device was 1-2 rad/s, the negative pressure of fan was 4-5 kPa, and the diameter of suction hole was 2.4-2.8 mm. On this basis, the field experiment was carried out, with the rotation speed of seeding disc, negative pressure of fan and diameter of suction hole as the test level factors, and with the index of qualified rate of seeding spacing, index of leakage rate and index of replay rate as the evaluation criteria, the orthogonal experiment with three factors and three levels was carried out. Design-Expert software was used to construct the mathematical regression equation and response surface model, and the influence of each parameter level on the qualified rate index of seeding was analyzed. The optimal combination of structural parameters was determined by using the software optimization module: the rotation speed of seeding disc was 1.3 rad/s, the negative pressure of fan was 4.6 kPa, the diameter of suction hole was 2.5 mm, and the field experiment verified that the pass rate index of seeding spacing of seeder was 92.35%, the leakage rate index was 3.97%, and the replay rate index was 3.68%. Meet the agronomic demand of white radish precision seeding.