Abstract: Ordovician limestone water is the main water disaster and key control object in Dongtan mine for safe mining of lows eams. Ordovician limestone water pressure reaches to 7.20~11.46 MPa in low seams. Without consideration of the influence of floor mining failure, water inrush coefficient of Ordovician limestone is 0.077~0.158 MPa/m and the minimum value is close to limit value(0.10 MPa/m) of the regulations. For finding out the hydrogeological condition of Ordovician limestone aquifer and formulating control measures of Ordovician limestone water, we built the hydrogeological model based on the hydrogeological conditions of the mine and dewatering test of Ordovician limestone, and calculated the hydrogeological parameters of Ordovician limestone aquifer using the computer simulation software Visual Modflow. By model validation, the hydrogeological model can reflect the natural flow field of Ordovician limestone, providing the reliable basis for prediction of water inflow in the mine and dewatered volume of Ordovician limestone.