Abstract: The Xiashu loess slope is widely developed in Nanjing area, which is easy to cause landslide under the condition of heavy rainfall and poses a great threat to people's life and property safety. In this paper, the typical Xiashu loess slope in Nanjing is selected as the research object. This article conducts on-site investigation of the landslide, and explores the basic characteristics of the slope, and analyzes the deformation and failure mechanism of the landslide, and uses numerical simulation methods to analyze the slope stability. The research results show that the slope is in an unstable state under rainfall conditions, and is basically stable under natural and earthquake conditions. Based on the stable state of the slope, support design and analysis were conducted, and the research results show that the stability of the slope after support is significantly improved compared to before support, and it can maintain a stable state under various working conditions. The slope treatment is practical and effective.