Based on a case study of the incision terrain at Ximayu, landslide erosion, forming characteristics, deformation and destruction characteristics are qualitatively analyzed. Results show that the Ximayu landslide-body is unstable. The authors constructed a geological model and a math-mechanical model, and then calculated the landslide body by means of finite elements. The result shows that stress has concentrated on the failure plane, which further supports the evidence that the Ximayu landslide is unstable and may move under heavy rainfall conditions, due to an earthquake or as a result of human activities such as slope cutting. It is suggested that engineering measurements be conducted in order to determine methods for stabilization and the prevention of further erosion.