It is difficult to detect the nighttime lane lines which showed darker and uneven lighted, for overcoming these problems, a lane recognition method was proposed. Firstly, edge enhancement based on Laplacian was used to enhance the pre-processing images’ edge. Then, image edge was detected by canny based on Otsu algorithm and the straight line of a third at the bottom of edge image was detected by Hough transform. Finally, an inside lane line extraction algorithm was proposed on the basis of slope constraint and realized marking the inside lane that the vehicle driving on. By experimenting with various lane markers, this algorithm can realize the lane line detection. The proposed approach can overcome the influence of uneven light and be able to eliminate the interference from the side lane line, guard rail, etc. Lane line detection is conducive to the vehicle running on its road.