Abstract: The influence factors of the geological environment in mining area are usually characterized by diversity and uncertainly,which caused the quantitative evaluation of geological environment in mining area is difficult.In order to improve evaluation accuracy of geological environment in mining area,taking the area of Ningxia as the study example,a new quantitative evaluation of geological environment in mining area based on fuzzy analytical hierarchy process (FAHP) and variable fuzzy set is established.Firstly,the evaluation indicator system based on the 4 grade I indicators of geological background of mining area,geological hazard,resource destruction and environmental pollution,and the 16 grade II indicators of engineering geological conditions,topographic features,hydrological meteorology,human activity intensity,etc.is established;secondly,the weight vector of the evaluation indicators are calculated by using variable fuzzy set,and geological environmental grade values can be obtained by adopting FAHP method,the grade of the geological environment in mining area can be divided based on the geological environment grade values.The study results show that the geological environmental grade value of the study area is 2.489,the comprehensive geological environment belongs to grade II,which inferred that the geological environment of the study area is generally good;the geological background of mining area,geological hazard and environmental pollution of the study area are belongs to grade II,resource destruction is belongs to grade III,which is indicated that resource destruction degree of the study area is in warning status,therefore,the protection degree of mineral resources,land resources and water resources of the study area should be strengthened,so as to realize the goal of sustainable development.

Key words: Geological environment in mining area, Fuzzy analytical hierarchy process, Variable fuzzy set, Quantitative evaluation model