Under bad weather conditions, the quality of the image we get will be seriously affected. Therefore, we must restore and improve the image quality and enhance the image to meet the needs of human observation or subsequent processing. In recent years, an image enhancement technology based on Retinex algorithm has attracted wide attention because it is not affected by illumination and can better restore the original appearance of objects. In order to solve the problem that the details of the existing image enhancement algorithms are blurred when they are enhanced in foggy days, this paper will study the image defogging enhancement technology based on Retinex algorithm. The experimental results show that the clear processing method of foggy images in this paper has a good effect, but it needs a certain sample training time, and the higher the accuracy, the longer the time it takes, so it has certain algorithm complexity. From the subjective observation, this algorithm has better detail expression ability, eliminates the “halo artifact and at the same time, inhibits the over-sharpening phenomenon on the premise of ensuring hierarchy. Therefore, Retinex algorithm makes the defogging effect better under the condition of low complexity.