The numerical method was an effective mean for solving ground water flow problems in heterogeneous or anisotropy aquifers and other complex conditions, which can describe the aquifer characteristics accurately. West third mining area of Wugou Mine in Huaibei of Anhui Province was illustrated as an example in this paper, outflow test data were utilized to build the hydrogeology conceptual model and its mathematical model with the objective reality, ground water simulation software—MODFLOW was used to simulate variation characteristics of the limestone aquifer flow under coal seam floor and achieved optimal hydrogeological parameters, as well as drainage volume under the condition of safe water inrush coefficient, and provided the theory basis for safe mining.