Abstract: A portion of zone III of burnt rocks is needed to be exposed in the southeast of the first mining area in Dananhu northern surface mine, making the water in burnt rocks become the main source of mine water recharge. Hydrogeological data in exploration stage show that water bearing space is developed, the permeability is high, the water reserves are large. But because of the constraints of hydrogeological exploration engineering amount, hydrogeological conditions could not be investigated in detail. The available hydrogeological data could not meet the requirements for the design of water drainage in burnt rocks in first mining zone. Simulated pumping test was conducted for groundwater resources of the burnt rocks, we obtained the hydrogeological parameters of burnt zone III. By using the numerical simulation method and MODFLOW software, we built the numerical model of groundwater in burnt zone III, calculated the groundwater reserves in burnt zone III. Through verification, the simulation results coincided with the actual situation of the mine, and can be used as the dewatering design basis in the first mining zone.