In order to grasp the water filling characteristics of the mine during the mining of No. 5 coal seam in Zhengyi Coal Industry, numerical calculation, numerical simulation, on-site monitoring and other methods were used to study the water inrush characteristics of the working face, and the development height of the water conduction fracture zone was determined to be 20 m, and the floor plasticity The destruction depth was 7.5 m, the water inrush coefficient of the floor 0.026 MPa/m, and without the risk of water inrush from the bottom ash confined water. It was determined that the normal water source of the mine was the water content of the sandstone fissures in the Shanxi Formation of the upper Permian, and the working face was predicted that the largest water inflow was 271 m3/h, and the research results provided basic technical data for the prevention and control of mine water damage.