Abstract: Evaluation of the high slope stability is very important in engineering construction and control of landslide disasters. By determining the weights of evaluation indexes in the fuzzy analytical hierarchy process, an index system and the grading criterion of high slope stability are established. The model of fuzzy analytical hierarchy process and the set pair analysis (FAHP-SPA for short) are integrated as the model of evaluation. The research results of FAHP-SPA applied to the high slope of a permanent shiplock at Three Gorges Project show that FAHP-SPA has distinct statistic and physical concepts, visual computation method, high precision and simple, effective but perfect scheme of modeling, therefore, it can be applied to slopes and other different comprehensive assessment problems under the known grading evaluation criterion.