The No.8105 face in the No.1 mining area of No.4 layer of Yugou Coal Industry belongs to the mining area under pressure. During the mining period, it was threatened by the floor water inflow affected by the adjacent DF2 fault fracture zone. In order to solve the threat of lagging water outburst in the production process of the mine, the fault water conduction control and water prevention technology were studied through theoretical analysis, electrical detection and grouting reinforcement. The change of water inflow before and after the mining treatment of the working face and the change of fissure water inflow before and after the fault treatment were determined. After the floor grouting reinforcement for water plugging, the treatment effect was obvious, the water volume during the mining period was obviously reduced, and there was no lagging water outburst phenomenon after the mining, which realized the safe and efficient mining of the working face.