This article designs an electro-hydraulic steering system to solve the problems of poor steering stability during the operation of multi axle vehicles. Firstly, a two degree of freedom four axis mathematical model was established, and the correctness of the mathematical model was verified by setting a vehicle model in Trucksim. A driver preview model was established to simulate the real driver environment, and a sliding mode controller was designed based on the ideal yaw rate and ideal center of mass sideslip angle. An electro-hydraulic steering system was designed based on the principle of hydrostatic transmission. Through joint simulation, the steering system was validated under the commonly used high-speed dual front axle steering mode and double lane changing conditions, while the steering wheel angle step input was verified under the all wheel reverse steering mode. The simulation results show that the designed electro-hydraulic steering system can reduce the minimum turning radius of the vehicle by 21% compared to the dual circuit hydraulic steering system, effectively improving the vehicle’s handling stability.