Abstract: According to the geological conditions of F₁₆ fault of Wugou Coalmine, it used the simulation test of similar materials, on the basis of solid-liquid two-phase similarity, to study plastic damage law of the coal pillar and the fault activation water inrush law of roof, floor and working face ahead when approaching fault mining. The results showed that the higher concentration stress formed in the roof and floor of coal pillar because of the barrier effect of fault zone. The water inrush risk was greater in the larger permeability of bottom strata rock. For the same width of coal pillar, the greater water pressure of aquifer was, the greater water inrush risk was.