Abstract: In view of the problems facing the research and development process of corn harvesting equipment, such as long research and development cycle, high cost, high sensitivity to environmental factors, and the need for a large number of field tests, this paper carried out a virtual simulation design and harvest test of corn ear harvester based on Unity3 D. Firstly, the overall design of the virtual simulation system of corn ear harvester, design of key modules of the virtual simulation system, and design of the physical components of corn ear harvester and the plant were completed. Secondly, optimal combination of parameters affecting yield loss rate of corn harvester was obtained by virtual single factor test and orthogonal test with yield loss rate of corn harvester as the response index and moving speed of corn harvester, height of cutting table, and planting density of corn as response factors. When the speed of harvester was 2.986 m/s, the planting density of corn was 6.7 plants/m~2, the height of cutting table was 0.42 m, and the lowest fruit leakage rate was 2.17%. Finally, the field verification test was carried out using the optimal parameters. The results showed that the average leakage rate of corn harvester was 2.36 %, which was consistent with the optimization results and met the harvest requirements of corn ear harvester.