Abstract: Firstly adopt limit equilibrium method and strength reduction method to carry through two-dimensional analysis of slope stability, and contrast analysis result to validate veracity and feasibility of strength reduction method. Secondly contraposing the three-dimensional influence of slope excavation, reinforcement and tunnel excavation, adopt three-dimensional elastoplastic FEM strength reduction method to analyse slope stability, analyse the safety factor, E-equivalent strain, displacement distribution and major stress distribution. The result indicates that reinforcement measure may obviously improve safety factor of slope stability, and three-dimensional strength reduction method is obviously preponderant in rock and soil engineering domain.