Geologic hazards being induced by phosphate mining badly threaten the life and property security of Yuan'an residents. This paper, taking Yanchihe phosphate mine as example, gives a general introduction of phosphate exploitation rang, methods and distribution characteristics of mined-out area, analyzes the deformation mechanism. Meanwhile it takes mining H/M ratio to make the qualitative assessment of geologic stability, works out the H/M value via GIS software fitting and stability zone chart. Three degree stability of Yuan'an Yanchihe phosphate mine are subdivided: area lack of stability, little unstable area and comparatively stable areas. And sta- bility assessment and correspondingly preventive suggestions are giving for those different areas.