Abstract: Geological environment quality assessment system and model are established with 13 first level assessment factors such as topographic grade and second level assessment factors i.e. nature geological characteristic. The evaluation area is divided into three parts: good quality geological environment area, ordinary quality geological environment area and bad quality geological environment area. Based on this, the geological environment quality is assessed with the method of double-fuzzy comprehensive assessment. And the result is: good quality of geological environment area 26.7%, ordinary quality of geological environment area is 52.4%, and bad area 10.9%. Therefore the geological environment quality of YunCheng is not bad, which provides basis for proper countermeasure of protecting environment and sustainable development.