In order to reduce the stress concentration of the circular saw blade of the shrub harvester, improve the heat dissipation effect of the circular saw blade, reduce the deformation caused by thermal expansion, and improve the service life of the circular saw blade, the paper adopts the variable density method, and uses the method of finite element simulation to optimize the topological design of the circular saw blade of the shrub harvester. Fixed constraints and dynamic loads are added in the optimization to simulate the actual working conditions, and finally the pseudo-density cloud image of the circular saw blade is obtained, and according to the obtained pseudo-density cloud, the circular saw blade is further structurally designed. The study shows that the optimized structure can improve the problem of stress concentration of circular saw blades, which plays a role in improving the life of circular saw blades.