By taken the ACY6type LHD hydraulic steering system as the research object, the system uses the articulated hydraulic steering system, hydraulic steering system and the working hydraulic system with dual pump confluence technology. The working principle of the system, the action actuator and suffered payload were analyzed. On this basis, the Automation Studio simulation software was applied to build a mechanical hydraulic steering systemhydraulic coupling simulation model to simulate the dynamic process for the system, and to get to the characteristic curve of steering system and steering actuators in place working condition. In order to achieve optimal design of this kind of vehicle hydraulic steering system, theoretical reference and technical support are obtained, with certain practical engineering value.