In view of the problems of large amount of fertilizer application, uneven application and inaccurate positioning of sweet potato fertilization machines at present in China, considering the distribution law of sweet potato roots and the characteristics of sweet potato planting patterns, a ridge-core arc-shaped uniform positioning fertilization technology was proposed in this paper. The arc shaper and spiral groove wheel fertilizer discharger are designed, the influencing factors that affect the uniformity of fertilization are analyzed, and the optimal working parameter range of the fertilizer discharger is determined. Furtherly, the rotation speed of the fertilizer discharge shaft, the spiral angle and the depth of groove are recognized as the test factors, the fertilizer discharge amount and the uniformity coefficient of variation of the fertilizer discharge are used as the indicators to carry out the quadratic regression rotation combination test. At the same time, the discrete element method is employed to simulate the process under different parameter combination settings, and the optimal parameter combination is obtained when the lift angle of the sheave is 79°, the groove depth is 3.7mm, and the speed of the fertilizer discharge shaft is 46r/min. Under the premise of the amount of fertilizer, the coefficient of variation of fertilizer discharge is smallest. By comparing with the actual operation effect, the simulation results are basically consistent with the field test conditions, which verifies the validity of the simulation test and the establishment of the regression model. This research can realize the uniform application of fertilizer in the ridge core at a certain depth and quantity, which can effectively reduce the amount of fertilizer application, improve the yield and the uniformity of sweet potato. At the same time, it provides a reference for the research and design of the sweet potato ridge core arc fertilization equipment.