The method of deep loosening and full-layer fertilization can prepare a sowing belt suitable for seed growth and development. It is a combination of plowing and no-tillage. It takes both “free” and “tillage” into consideration, which is a superior protection. Full-layer deep loosening fertilization is of great significance to improve fertilizer utilization and reduce environmental pollution. To satisfy the crop nutrient requirements of a different growth period with one-time fertilization, and improve fertilizer utilization, a subsoiling full-layer fertilizing shovel suitable for corn planter was designed. The angle between the subsoiling shovel, fertilizing tube, and fertilizing plate was analyzed theoretically and designed, and the theoretical values of key parameters were obtained. The experiment with quadratic regression rotation combination design was designed, which taking uniform variation coefficient of fertilizer as response index, working speed and working depth as influencing factors, and using EDEM to establish a discrete element simulation model of the subsoiling full-layer fertilization shovel, the working process of the subsoiling full-layer fertilization shovel was simulated and the experimental data was obtained through simulation analysis. Design-Expert was used to perform variance analysis and response surface analysis on the experiment data to obtain the optimal working parameter combination, which were as follows: the working speed was 3.81m/s, and the working depth was 25.22cm. Field experiment results showed that under the optimal working parameters of this design, the coefficient of variation of fertilizer uniformity was 41.05%, 24.11%, 20.31% and 14.63%, and the relative error between the experimental value and the theoretical optimization value was 10.89%, 4.06%, 2.37% and 3.10%.