Abstract: A parametric model for the tensile-shear spot welded structure of ultra-high strength steel was established with software ANSYS by APDL to analyze the static strength of the structure,and was verified with experiments. Based on the simulated results,the optimized model was built to decrease the whole materials,and some sizes of the structure were also optimized. The response surface methodology was adopted to make the stress constraints explicit,and the sequential quadratic programming algorithm was used to achieve the most suitable solutions of the optimized model. The results show that this method could effectively enhance the solving efficiency and avoid oscillation. The calculation procedure was programmed with C language in order to improve efficiency,and the results indicate that the optimization was feasible and effective.