Aiming at the low accuracy of existing nighttime image visibility detection algorithms,this paper proposes a nighttime visibility classification algorithm based on stable light sources.Firstly,all stable light source street lights in the image are detected by the target detection network,and all light source blocks in the image are obtained.Secondly,the light source blocks are fog classified by the classification network.At the same time,all the light source blocks are sorted by size and average size and the corresponding weights are obtained. Finally,the visibility levels of nighttime images are classified after combining the classification results of light source blocks with their weights to conduct statistical analysis.The experimental results show that the accuracy of the nighttime visibility classification algorithm in this paper reaches 77.6% in the real social dataset,and the classification results are more accurate than the existing methods,and have good generalization in different scenarios.