Ion adsorption type rare earth ore is an important rare earth resource in China and its main mining method is in-situ leaching.Liquid injection activities in in-situ leaching will affect the safety and stability of mountain slopes.Therefore, ensuring the safety and stability of mountain slopes in the process of in-situ leaching is always a difficult problem to be solved urgently.In this paper, the characteristics of in-situ leaching engineering are analyzed, the main influencing factors of slope stability in in-situ leaching process of ionic rare earth ore are studied, and a hierarchical analysis model of slope stability evaluation is established which could consider the influence of leaching process.The hierarchical model consists of 2 levels, 5 categories and 11 indexes.The weight of indexes considering the influence of leaching process is calculated by using AHP hierarchy method and grey relational theory.The evaluation system proposed in this paper is applied to the actual leaching engineering, and the calculation results are compared with the analysis results of limit equilibrium method.The results show that the method is simple and feasible, and the conclusion is reliable, which can provide reference for decision-making of in-situ leaching project.