Abstract: The phenomenon of the sliding face cross over the anti-siding pile has often occurred in the actual engineering, but at present its calculation theory is not mature at all, and many problems in the calculation process are dependent on artificial hypothesis. The Chenglongyihao landslide of Sichuan As an example, the author using FLAC3D to simulate the variation of the stress field, displacement, shear strain increment and distribution characteristics of the plastic zone of the landslide in the dynamic deformation, and calculate the stability by using strength reduction method. Besides, the author has also studied the mechanism of the Sliding Face Cross over the Anti-side pile of high slope under rainfall condition, and tried to solve the reasonable position of anti-sliding pile. The results show that:(1) There is a potential slip surface in Chenglong landslide before setting anti-sliding pile. After setting pile, the landeslide generate new shear surface on the top of piles and will cross over the anti-slide pile; (2) the failure of the sliding face cross over the anti-slide pile of high slope was controlled by the position of anti-sliding pile. The increasement of anti-sliding piles height and when the piles were arranged on the position of the shear outlet of the sliding surface, the ability of anti-sliding can be full used, in addition, which can prevent occurrence of the phenomenon of the sliding face cross over the anti-siding pile effectively. The reliability of FLAC3D numerical simulation results is verified by the field monitoring data, which indicates that the method is suitable for the analysis of overtopping, and can be popularized in the field of rock and soil research.