Abstract: Fault activation induced by mining disturbance is the key factors for water inflow increase.Through the tests of complete stress-strain-seepage，the geological model and the numerical calculation models are established.The effect of mining disturbance on fault activation and the effect quantization are analyzed.The research results showed that the permeability of post-peak rocks is about 2 times of that of the pre-peak rock.The through permeability of post-peak rock crack has changed in nature.Geological model of open pit shows that faults at overburden rocks are the main water channel and significantly influenced by underground mining.The displacement value at the right side of the slope is four times of that at the left side，so it is easy to occur water inflow increase and landslide risk caused by the displacement of rock at faults.According to the displacement gradient change，the mining-disturbed area can be divided into five regions:rock falling zone，transition zone，deform-moving zone，micro-deforming zone and undisturbed zone.The research result is helpful to optimize the arrangement of ground grouting curtain.

Key words: Fault, Mining disturbance, Water Conducted, Displacement gradient