Abstract: With the rapid increase of transportation and construction tasks of various heavy equipment and large components, the demand for large carrying equipment is increasing. Aiming at the design problem of steering linkage system of modular axis transport vehicle, a digital design method of steering linkage system is proposed. Based on the theory of the connecting rod steering system of multi axis vehicle, the function modules of SolidWorks and the optimization algorithm of MATLAB are developed and called by python, the digital design platform of the connecting rod steering system is established, and the graphical user interface of human-computer interaction is designed. The hole position layout of the connecting rod steering system can be optimized and adjusted according to the needs of users, so as to realize the optimal steering angle, and the parameters are transmitted to the three-dimensional model, Realize parametric design and automatic assembly. Taking the three-axis connecting rod steering system as an example, the parametric design and optimization are carried out. The angle error is reduced to less than 2.4°, which improves the steering accuracy of the axis vehicle. The design efficiency is increased by about 45%.