The tracked vehicle with a fully hydraulic driving system, which has a strong traveling performance of passing and mobility ability in the complex terrain, is a typical system of mechanical-electrical-hydraulic integration. At the same time, for the good low-speed stability of the hydraulic system, this vehicle is widely applied in most engineering projects. However, for the complexity and unpredictability of the motion state in the complex environment and the power matching of the driving system, the driving path of the tracked vehicle with hydraulic driving is difficult to control. Moreover, for the complicated interaction between mechanics, the establishment of the mathematical model is much more complex, and the traditional mechanics-control and hydraulic-control co-simulation can not accurately simulate this physical phenomenon.The kinematic and dynamics characteristics of the tracked vehicle are studied firstly, and the dynamics model is built. Meanwhile, the hydraulic system is also established with the analysis of the closed loop hydraulic system. According to the kinematics and hydraulic characteristics, the path tracking controller is designed. The co-simulation model is built based on the control system. Then dynamic connections of the mechanical-electrical-hydraulic system are implemented, and the validity and stability of the control strategy and hydraulic system are verified and evaluated. The results show that the vehicle can track the path effectively in a certain range of error, and the hydraulic system has good stability and reliability. In addition, this co-simulation with mechanics and hydraulic and control system research method is proved to be feasible, which also reflects obvious advantages of modeling and control system design.