There is a problem of insufficient pushing angle in the seedling picking mechanism of the complete non circular gear planetary gear system, while there is an impact on the seedling picking mechanism of the incomplete non circular gear system. A non circular complete gear planetary gear system seedling picking mechanism was designed with a large pushing angle that met the requirements of vegetable seedling picking. Based on Fourier function, a quadratic unequal amplitude transmission ratio curve was designed, and the influence of Fourier function coefficient on the seedling path was analyzed. The change relationship of Fourier function coefficient on the transmission ratio curve and the angular displacement of the driven gear was studied. The change law of Fourier coefficient on the dynamic parameters of the seedling picking mechanism was revealed. The change relationship of Fourier function coefficient on the seedling picking angle and the seedling pushing mechanism was deduced. Manufacturing and assembling the seedling picking mechanism. Based on the virtual prototype and high-speed camera technology, the rotation test of the seedling picking mechanism was carried out. The feasibility of the design of seedling experimental values of the seedling picking trajectory was done. The seedling picking mechanism was tested on the platform. The success rates of the seedling picking mechanism at different rotational speeds (40r/min, 50r/min, 60r/min) were 94%, 90% and 88%, respectively. The feasibility of the design of the seedling picking mechanism was further verified by the seedling picking experiment.