To realize the lane marker line identification in complex variable light environment and ensure all-weather lane departure warning, a new lane marker line identification algorithm is proposed. The adaptive image segmentation technology based on OTSU algorithm is used for the lane marker line division for different lighting conditions, and then the adaptive threshold is obtained the weighting process for global and partial thresholds. Sobel operators with gradient directions of 45°and 135° are adopted to extract the lane edge information. Finally, improved Hough transform method is used to finish the lane marker line identification. The road images under different lighting conditions are compared, and the results show that the identification accuracy of the proposed method is improved by 5.7% on average compared with that of the traditional Hough transform method, and the average detection time of a single image is 57.79 ms. The proposed algorithm has good anti-interference performance, can adapt to various lighting conditions, and can meet the real-time requirements of the system.