Abstract: An important technology in the area of Intelligent Vehicle(IV) is how to accurately calculate the angle between the moving orientation of the vehicle and the driveway, most of the literatures nowadays have a hypothesis that the optical axis of the camera is parallel to the ground, so the installation error of the camera has been neglected. This paper achieved the angle detection between the moving orientation of the vehicle and the driveway based on monocular vision, detailed technical realization scenario has been given, and we emphatically analyzed the rectification method under the circumstance of there is an angle between the optical axis of the camera and the ground, by using our method, the effect of the installation error towards the detection results can be greatly decreased, so this paper has broaden the application scope of angle detection technique and has made it become more robust, images captured from the real scene also validated the accuracy of our method.