Abstract: According to the specific geological conditions, taking F₆ fault of Wugou Coal Mine as the research object, combined with the research of fault and the floor limestone water in the area of space distribution relationship, numerical simulation and theoretical analysis are used to analyze the water inrush risk of different widths of coal pillars, and theoretical calculation is used to determine the reasonable width of coal pillars before F₆ fault treatment, at the same time, considering the 3D seismic exploration results of F₆ fault and the data of underground excavation, the grouting reinforcement range of the lower aquifer is analyzed theoretically. Combining the results of theoretical calculation and numerical simulation, the feasibility of reducing the coal pillar of F₆ fault is studied. The research results have important significance for improving the recovery rate of coal resources in Wugou Coal Mine.