Abstract: Abstract: In order to solve the problem of poor growth quality of pot seedling caused by large soil disturbance and low soil porosity of the hole wall during the hole forming process of soil opener for rapeseed transplanting machine, simulation analysis of the hole forming process of two different types of soil openers was carried out by using the discrete element method software EDEM according to the physical size parameters of rapeseed pot seedlings and the agronomic requirements of transplanting pot seedlings of rapeseed in this paper. The discrete element method was used to establish and modify a soil model consistent with the physical and mechanical characteristics of the soil in the test bin. In combination with the movement trajectories of the two different types of soil openers, hole forming method (soil picking type and soil extruding type) of soil openers, bottom size of soil opener and soil opening depth were chosen as the test factors. The soil return coefficient in the hole section and the soil porosity of the hole wall were chosen to evaluate the effects of various test factors on hole morphology and soil disturbance. The discrete element method simulation results showed that soil picking type soil opener was a relatively superior method for hole forming. The soil return coefficient in the hole section and soil porosity of the hole wall of soil picking type soil opener were better than that of the soil extruding type soil opener. The section shape of the hole formed by the picking type soil opener with square structure at the bottom was a rectangle. The longitudinal length of the top of the hole was less than the width of the top of hole, and the longitudinal length of the bottom of hole was larger than the width of the bottom of hole. The optimal parameter combination of the soil opener required by agronomic hole size requirement was obtained as follows: the bottom size was 50 mm, the soil opening depth was 40 mm, the length and width of the hole top size formed by soil picking type soil opener was 69 mm and 79 mm respectively, the effective depth was 40 mm, the soil porosity of the hole wall was 48.5%, and the soil return coefficient in the hole section was 0.08. Physical soil bin test was carried out to verify the operating performance the soil opener. The soil in the test bin was treated so that the soil conditions of the simulated soil were consistent with those of the soil in the test bin. The results of soil bin test showed that the average error between the simulation results and the soil bin verifying test results of the longitudinal length of top, width of top, effective depth, soil porosity of the hole wall and the soil return coefficient in the hole section of the hole formed by soil picking type soil opener were 4.8%、3.4%、1.2%、1.5% and 14.2%, respectively, the optimized soil opener could form holes that meet the design requirements. This study provides a reference for the next step of optimization of soil opener.