Abstract: In Xuzhou Coal Mining Area the groundwater hazard is serious due to the larger mining depth and complicated hydrogeological conditions.The causes of water bursting,which source is Ordovician(O) aquifer,are as follows:hidden collapse column in coal seam floor or the fault is transmissible for groundwater;the floor(roof) aquifer connects to O aquifer,fracture zone of coal seam roof conducts with O aquifte that is located in opposite side of the fault;O groundwater recharges the mine through buried outcrop of bedrock laterally.The measures of groundwater hazard control are as follows:the development regularity of O karst water should be explored by advance technique;mining by areas and perfecting drainage system;plugging water bursting points with grouting;combining drainage with water supply and synthetically utilizing water resources.