The objective of this research is to integrate a method of optimization of structures to the Computer-Aided Design (CAD) process with a mesh quadratic. Uses ANSYS software to perform static finite element analysis on a bracket model. On this basis, the homogenization method is adopted, and the total flexibility of the model is taken as the objective function, and the volume is used as the constraint condition. The topology optimization design of the model under several working conditions is carried out. The problems of basic model establishment, optimization region selection, optimization process control and optimization result analysis and application in topology optimization design process are discussed. The application of topology optimization in the initial design process of automotive structures is realized.