Abstract: Problems of displacement and stability of the excavation slopes reinforced with steel bars by FEM are discussed. Quadriateral slide elements were used in analyzing to-simulate the boundary properties between soil and steel bar. Rather more, Griffith-Mohr failure criteria was used firstly to solve problems of tension-shear,coupling failure. Comparison between analytic solution and simulated test shown that the solution by this method conforms to the actual situation. This method provides both scientific basis for theroetical research and method of prediction and optimization in engineering design.