Abstract: In order to solve the problems of poor reliability, high failure rate and poor process effect of grain equipment in China, the multi-objective coupling optimization design technology for grain equipment was put forward in this study. According to the present situation of grain equipment manufacturing industry, the classification and characteristics of grain equipment such as flour processing and rice processing were analyzed. The technical system model of multi-objective coupling optimization design for grain equipment was established. The key technologies were presented in detail, including the rapid generation of grain equipment serialization model, structural strength sensitivity analysis, structural reliability sensitivity analysis, process performance parameter sensitivity analysis and multi-objective coupling optimization design method. Based on the above key technologies, a digital design platform for grain equipment was designed and developed. The practical application case showed that this technology is of great significance to improve the comprehensive performance of grain equipment.