With coal mining, the upper group coal resources are gradually depleted and the mine extends to the lower group coal. The main threat of water damage in mining lower group coal is the pressurized water of Ordovician tuff. In the process of coal seam mining with pressure, the prevention of ash water burst becomes the top priority of water damage prevention and control in mining lower group coal, in which the water-conducting fault is one of the most important water-conducting channels to induce ash water burst. In order to effectively seal the water-conducting channel generated by the fault, Handan Guo’erzhuang Mine of Jizhong Energy Group adopted ground directional drilling combined with ground grouting technology to grout and reinforce the tension fault (F292 fault) near the explored coal mining face, finally achieving the purpose of sealing the water-conducting fissure of the fault and reducing the risk of water outburst. The practical results showed that the implementation of the project has effectively transformed the water conductivity of the F292 fault and achieved safe production.