The Soil arching effect, the transfer of soil pressure from the yielding soil to the piles support, is a phenomena commonly encountered in geotechnical engineering for stabilizing landslides. In this paper, the (finite element method) FEM and (discontinuous deformation analysis) DDA were used to study on the soil arching effects of stabilizing piles in landslides. This paper proposes a method for two dimensional numerical simulation to perform three dimensional soil-pile interaction so that the slope angle can be considered even using a two dimensional numerical method. And then, a FEM model is built based on the FEM to investigate the soil arching effect on stress and deformation distribution in detail for different pile intervals and pile width. The results shown that the soil arching effects do exist and the height of soil arching becomes larger when the pile interval is larger; the soil arching height does not change when the pile width increases, while the shape of soil arching changes. Finally, in order to investigate the failure condition of a stabilizing pile enforced slope, DDA is applied. The results comparison between the example of FEM model and DDA model is conducted to verify the DDA application of solving the continuity problem. Then the failure of model is also analyzed by the simulation of DDA. The results show that the DDA has accordant results with FEM for the small deformation problems, and the DDA can be applied to simulate the large deformation and failure problems of soil arching which cannot be done by FEM.