The frame is an important subsystem for the FSAE race car, as it supports and connects to other subsystems. The weight, frequency and structure of the frame influence on the race car performances such as acceleration, handling, ride and durability. A rigid-flexible coupling FSAE race car model with flexible frame is implemented in ADAMS/car. By extracting the forces and torques of the joints which connect the frame to other subsystems in various race car extreme conditions, the loads transfer path from road and aerodynamic forces to the frame is discussed. The strength, stiffness and free mode analysis of the frame are carried out by means of Finite Element Analysis (FEA), the stress analysis and checking are under loads extracted from dynamic simulation with the rigid-flexible coupling FSAE race car model. According to the FEA results, an optimization of the frame is implemented by topological and size optimization. The optimization result shows that the optimal frame has an obvious lighter weight and greater strength and stiffness; the low-order natural frequencies get better performance as well. This paper gives an instructive significance for the FSAE race car frame design and debugging, and the testing results also verify the effectiveness of this study.