Abstract: A variable density and multi-load topology optimization method for rocket sled chassis design is developed.Key points of optimization design for rocket sled chassis are analyzed.With the optimization method,modeling and solving of optimization design for rocket sled chassis are implemented on basis of ANSYS system.The result of optimization for rocket sled chassis is processed and analyzed,and the optimized structural layout of the rocket sled chassis is obtained.The instance result show that this method can be used to improve the quality and efficiency of product design and provide a reference for the designers of rocket sled.