Abstract: In order to improve the stability of 4YZS-4 type corn for seed harvester，mechanical model of ear box bracket under typical operating conditions was built.By finite element simulation，position of maximum stress and maximum displacement was found and then the structure was optimized.Maximum stress，maximum displacement and maximum displacement of Y direction of ear box bracket reduced by 5.6%，6.8% and 26% after optimization.It provided reference for the future design of corn harvester ear box and bracket.