The engineering geological investigation of potential landslide at sewage outlet of Xi′an Xianyang International Airport shows that the stability of slopes has basically reached the limit equilibrium state.The safety factors of the landslide stability was calculated respectively by two-dimensional and three-dimensional limit equilibrium methods and two-dimensional or three-dimensional finite element method with parameters inversion of two-dimensional limit equilibrium Bishop method and statistical parameters of quick shear test.The results show that the factors of safety from finite element method are on the high side

and that of two-dimensional limit equilibrium method is the smallest.The two-dimensional and three-dimensional limit equilibrium methods and two-dimensional finite element method should choose the average of the large values

while the three-dimensional finite element method should select the average of the small values.Finally

the prevention measures of cutting slope and pressing foot are presented on the basis of three-dimensional finite element simulation.