Abstract: With the development of artificial intelligence technology, many different fields have start to apply machine learning and deep learning technology. With the progress of research, deep learning technology has also begun to be applied to lithology identification. UAV images have the characteristics of agility, globality and ability to overcome unfavorable geographical conditions, providing high-resolution and detailed images for geological exploration work. On the basis of high-resolution UAV outcrop images, deep learning algorithms and graphic image processing algorithms are applied to outcrop lithology identification. This paper proposes an outcrop photo lithology recognition algorithm (CNN-SLIC) that combines convolutional neural network and superpixel classification algorithm. First, segment outcropping photos and constructed the dataset, and train a neural network model. Then, the neural network is used to identify the content of the image to determine the distribution of lithology; then the superpixel classification algorithm is used to delineate the boundary of the rock mass. Finally, melt lithology identification results and rock mass boundaries. In this paper, the algorithm of semantic segmentation is also used to identify the lithology of UAV images. Semantic segmentation is classification at the pixel level, which is more accurate than other object recognition methods.The CNN-SLIC algorithm can not only accurately identify the edge of the rock mass, but also accurately divide the lithology. The classification accuracy rate of CNN-SLIC reached 88.7%, while the method using semantic segmentation has higher accuracy for lithology recognition, but the recognition of object edges is not clear enough. This research not only has important theoretical significance for the development of outcrop sedimentology and remote sensing geology, but also has great significance for promoting the combination of artificial intelligence technology and geology.