Abstract: By applying strength reduction method and gravity increase method with the destructive criterion of the slope deformation variation tendency to stability analysis in 3D high slope of the hydroelectric station, the potential failure of 3D-sliding block and the corresponding factor of safety are obtained. Compared with the results of the generalized wedge method, the stability of the slope is evaluated.The result indicates that with the destructive criterion of the slope deformation variation tendency, the stability anylysis of 3D slope with strength reduction method and gravity increase method is rational and feasible.