Abstract： In recent years, the problem of sandstone water damage in coal seam floor began to be highlighted in some coal mines in Jurassic coalfield, which seriously affected the safety production and continuation plan of the mine. Based on the floor water inflow law and water quality test results of No.1301 face in Minxing Mine, the water filling factors were analyzed, and the water damage threat of coal seam floor aquifer was comprehensively evaluated. The research results showed that the water inflow from the floor of No.1301 face was mainly concentrated in the axis of syncline structure, and the water inflow from the floor mainly came from the sandstone aquifer of the direct floor of No.3 coal seam. The main water filling source of the mine was the sandstone aquifer water in the coal seam floor. The main water filling channels included the roof and floor mining fissures and the fissure development zone of the syncline structure axis formed by the coal seam mining disturbance. The water inflow in the floor of the working face was the result of the combined action of the more developed water-bearing sandstone and structure fissures in the coal seam floor, and the future continuation area was also threatened by the confined water of the floor sandstone.
