Objective Aiming at the seismic performance of truss bridges under the actual load the optimization framework of the truss bridge model based on the orthogonal test method is put forward and the fast economical and reasonable design method for bridges is obtained. Methods Starting from the conventional bridge model this method first establishes a simplified finite element model of a truss bridge. Bridge deck width bridge deck thickness and construction materials are selected as experimental factors and a three-factor three-level orthogonal numerical simulation experiment is designed. Secondly the variance analysis and regression analysis of the data of the finite element simulation results are carried out to study the sensitivity of the bridge structural parameters to the seismic performance index. Finally the accuracy of the optimized bridge model is verified by static and dynamic analysis. Results After the variance analysis and regression analysis of the orthogonal test data the results show that the width of the bridge deck has the most significant effect on the maximum stress followed by the thickness of the bridge deck while the density of the material has a minor effect. Through the finite element calculation structural deformations under stress and the vibration characteristics of bridge structures are analyzed and the structural feasibility of the bridge structure under stress and vibration is verified. Conclusion The combined application of the orthogonal test method and simulation software enables a rapid and effective understanding of the impact of various factors on bridge performance. This approach also provides a theoretical basis for enhancing the seismic performance of truss structures potentially promoting efficient bridge design and optimization methods.