Abstract: Based on the landslide project at K270+854 along the Lancang River Highway, and in consideration of the engineering geological environment and characteristics of ancient accumulation body, this study investigates the properties, deformation characteristics, and formation mechanisms of ancient accumulation landslides. By applying the transfer coefficient method, the parameters of the landslide surface are inverted, and the residual sliding force under different sliding surfaces and different conditions are analyzed to assess the stability of the landslide. Considering the loose structure of the ancient accumulation body, the large depth of bedrock and the reservoir bank stability factors, comprehensive prevention and control are carried out by using ultra-deep anchor cable anti-slide pile and water interception and drainage measures. The Lizheng geotechnical software is used to analyze the internal forces and displacements of the anchor cable anti-sliding pile. After more than 8 years of safe operation following landslide mitigation,practical experience has demonstrated the success of ultra-deep anchor cable anti-sliding piles in the mitigation of ancient accumulation landslides. This has significant implications for the design of similar prevention and control measures for such landslides.