Jiulong Mine with a very complex hydrogeology conditions, as the mining depth deepened, mining showed different hydrogeological laws from the shallow part. In the mining face of the 15252N working face of the Jiulong Mine, water inrush from the floor occurred during the mining process, which eventually led to the flooding of the 15252N working face. Although the working face was treated through the ground area, the floor water inrush still occured in the late stage of mining. By analyzing the cause of water inrush from the floor, the analysis and research of the prevention and control of No. 2 coal seam water in the deep mine was carried out.