This paper proposes an optimal control method to achieve the path tracking mission for the vision based intelligent vehicle. After the access of road trajectory, path tracking task is achieved by the intelligent vehicle automatic steering devices. The angle deviation and lateral deviation relative to the target path can be controlled in the smaller range by state feedback optimal control. A car model contained road information is established for the achievement of intelligent vehicle path tracking and automatic steering. Some values of the variables needed for the control system are obtained by sensors mounted on the car, and achieve the path tracking by the optimal state feedback controller. The algorithm proposed has been validated by simulations. It can make the lateral deviation within the expected range stability. And also the lateral acceleration meets the ride comfort requirements.