Abstract: On the basis of extensive analysis of geological tectonic characteristics in Zhaoguan Mine Field, taking 5 usual parameters as indexes for the forecast of the geological structure, the quantitative forecast model in un-mining area is built by grey system modeling forecast, and then the evaluation parameter values are forecasted. On that basis, combining with the 5 usual parameters, the fault fractal value, one of assessment factors of fuzzy comprehensive judgment, is applied to the quantitative evaluation of the structure, and the geological structure complexity of un-mining area is quantitative evaluated.