Abstract: Based on the analysis of geotechnical quality, calcutive mode, underwater, load and some other factors which can strongly influence the stabilization of landslides, this article sets utmost equations on assessing through the analysis of geotechnical parameter, underwater, effective gravity and other sensitive factors, and their distribution. By combining with the theory of reliability and the approach of First-order Second-moment, after the nonlinear utmost equation being linearized by using Thaler series,and combining with reliability method, this article works out a reliable index of the stabilization of landslides, that is β. At last, this theory is proved accurate by contrastive analysis on the stabilization of the landslide of Kangjiazui in Kaixian. Meanwhile, the accuracy to evaluating the stabilization of landslides is improved.