Abstract: The suspension system is an important component of electric vehicles, and the lower control arm is a key component for transmitting motion in the suspension system. The lower control arm transfers the force of the wheels to the frame and controls the movement of the wheels. With the increasing trend of lightweight electric vehicles becoming a hot research topic for enterprises, researchers have conducted extensive research on the optimization design of electric vehicle components. In this article, the topology optimization design based on SIMP method was carried out on the lower control arm of an electric vehicle. The weight of the optimized lower control arm was reduced by 35%. Then the mechanical analysis was conducted on the optimized lower control arm through finite element analysis, and it was verified that the strength and stiffness of the optimized lower control arm meet the requirements.