Abstract: This study focuses on the lower control arm of a passenger vehicle, aiming to enhance its modal characteristics and structural strength through a combination of finite element analysis and structural optimization. A finite element model of the lower control arm was established to conduct free modal analysis and strength analysis under extreme conditions, identifying its natural frequency distribution and stress concentration areas. Based on the analysis results, structural improvements were made using topology optimization and size optimization methods, followed by modal and strength validation of the optimized model. The results show that the seventh-order natural frequency of the optimized lower control arm increased by 3.7%, while the maximum stress under extreme conditions decreased by 17.6%, both meeting the design requirements. This study provides a reference for the high-performance design of lower control arms.