In single image, in order to recover the image in the foggy weather faster, and make it suitable for both foggy and haze weather, the method of dark channel prior and the Retinex method based on the theory of human vision are combined and improved. Estimation of atmospheric light intensity in the dark channel prior is improved and the color of haze image is rectified in the method, which make it suitable for both the fog and haze image. In addition, the transmissivity estimation in the method of dark channel prior is simplified. The simplified dark channel prior method and the Retinex algorithm are combined, which achieves real-time processing of the fog and haze image. Based on the experiment, this method has preferable efficiency on processing the fog and haze image in the application of monitoring road, while the real-time speed is also guaranteed.