A wind-delivered rice side-deep fertilization device was designed by integrating the advantages of a double-gear fertilizer feeder and a spiral fertilizer feeder to solve the problems of poor performance of fertilizer discharge caused by the clogging of fertilizer outlets at the end of fertilizer feeder in paddy field environments. The fertilization device for rice was overall designed and the parameters of the fertilization device were determined through theoretical calculations. Discrete element simulation analyses of key components were conducted with EDEM software based on the experimental results of material characteristic parameters. Experiments of single factor and Box Behnken response surface were performed to determine the optimal parameters using the coefficient of variation of fertilizer stability as the evaluation index， the diameter， pitch， and speed of the spiral axis as experimental factors. The optimal transmission ratio of the two-stage fertilizer feeder was determined by comparing its impact on the quality of fertilizer discharge. The effectiveness of the design was validated through comparative analysis of prototype tests between the two-stage fertilizer feeder and the single-stage spiral fertilizer feeder. The results showed that the optimal combination of parameter for the spiral axis was a diameter of 21 mm， a rotation speed of 140 r/min， and a pitch of 17 mm， with the coefficient of variation for discharge stability of fertilizer of 2.5%. The fertilizer was discharged continuously and evenly when the transmission ratio of the double-gear fertilizer feeder and the spiral fertilizer feeder was 1∶4. The results of testing the prototype showed that the coefficient of variation of the consistency， stability， and uniformity of the two-stage fertilizer feeder was improved compared to that of the spiral fertilizer feeder. It will provide a theoretical foundation and reference for the technology and equipment of rice side-deep fertilization， and valuable insights for the future studies in this field.