In order to solve the problem of high reseeding rate of sowing non-spherical seeds in vegetable seedling precision seeder, a kind of clearing device was designed, and the structural parameters of the clearing device were optimized through the simulation of flow field in the seed cleaning device. The stress and movement state of seed at the stage of seed absorption were analyzed. Through analysis, two seeds were usually adsorbed when the non-spherical seed was replanted, one of which was mainly sucked and the other seed was the secondary. Eggplant seeds were used as sowing seeds, and the seedling performance of the sowing machine was tested through the quadratic rotation orthogonal combination experiment. By means of variance analysis, the influence of each factor on the re-seeding rate was obtained from big to small as suction pressure, clearing pressure and vibration frequency, the influence of each factor on the leak seeding rate was obtained from big to small as clearing pressure, suction pressure and vibration frequency, the influence of each factor on the qualified rate was obtained from big to small as suction pressure, clearing pressure and vibration frequency. The mathematical model between three factors and the indexes was built. The law between three factors and the indexes was analyzed and optimized parameters were tested. Parameters optimization and verification tests were performed. The optimal combination of parameters were as following: suction pressure was 15.7kPa, clearing pressure was 3.3kPa, vibration frequency was 50Hz, and the re-seeding rate was 1.26%, the leak seeding rate was 1.75%, and the qualified rate was 96.99%. Under the same experimental conditions, the test results showed that the re-seeding rate was 1.4%, the leak seeding rate was 1.7%, and the qualified rate was 96.9%.