In this paper, apply "FEM strength reduction" to carry out slope stability analysis, at the same time, apply "Bishop's simplified method" to compare the result. Follow the reduction factor increases, the maximum horizontal displacement that at the top of slope was increased slowly in the initial stage, but when the reduction factor close to the safety factor, the maximum horizontal displacement was reduced quickly. And, follow the reduction factor increases, the plastic zones from scratch, until through. For comparing, I find the damage surface that calculated by the two ways,are basically consistent, but the safety factors are conservative by the "Bishop's simplified method".