In order to improve the utilization efficiency of fertilizers, reduce the amount of chemical fertilizers applied, and realize fertilization in the root zone of rapeseed, combined with agronomic requirements for rapeseed sowing and fertilization, the side deep hole fertilization process for rapeseed was proposed, and a kind of mechanical hole fertilization device was designed. The working process of the hole fertilization device was explained, the basic parameters of the device were determined through theoretical analysis, the mechanical models of fertilizer particle group in fertilizer filling and feeding zone were established, and the main influencing factors affecting its fertilizer distribution performance were determined. The discrete element software EDEM was used to carry out a simulation analysis on the fertilizer distribution performance of the fertilizer point-applied device, and the influence of rotation speed of fertilizer feeding unit, length of fertilizer hole and fertilizer tube on the error of hole fertilizer amount and the fertilizer distribution long axis was studied. The optimized result showed that when the fertilizer feeding unit speed, the length of the fertilizer hole and the fertilizer tube were 60r/min, 18mm and ABS fertilizer tube, respectively, the error of hole fertilizer amount and the fertilizer distribution long axis were 7.05% and 62.45mm, respectively. The bench test showed that under the conditions of rotation speed of fertilizer feeding unit of 30~90r/min, the error of the hole fertilizer amount was 4.56%~15.69%, the fertilizer distribution long axis was 76.32~91.50mm, the stability coefficient of fertilizer distribution long axis was 4.53%~9.78% and the error of fertilizer pointed distance was 3.24%~7.31%, respectively. Field test results showed that when the fertilizer feeding unit was 30~90r/min, the error of the hole fertilizer amount was 4.73%~16.07%, the fertilizer distribution long axis was 85.21~101.65mm, the coefficient of variation of the fertilizer distribution long axis stability was 4.82%~10.63%, the error of the fertilizer pointed distance was 3.36%~7.58% and the stability coefficient of fertilization depth was 6.43%~10.85%, respectively. The cavitation performance was well, and it met the requirements of hole fertilization.