Abstract: Accurate determination of the hydraulic conductivity of faults represents a pivotal and challenging task in mitigating water-related damage in faults within contemporary engineering practice. At present, the main technical methods to judge fault conductivity are field exploration and theoretical analysis. However, due to the high cost, long time-consuming, and lack of detailed theoretical analysis, fault water damage accidents occur frequently during the construction of underground projects. Seven main controlling factors of fault conductivity including aquifer docking ratio (ADR), mudstone smearing factor (SSF), section tightness index (I_σ), mudstone plasticity index (I_m), water-rock stress index (I_w), fault distance (D_f) and fault inclination angle (θ) were selected and weighted by IFAHP-CRITIC combination. The multi-factor coupling prediction model of fault conductivity is constructed, and a new concept of fault conductivity index is proposed. The model has been successfully applied to the quantitative and fine evaluation of water conductivity of Wangzhuang fault and Xiaosonglou fault in the natural state of Jiangzhuang Coal Mine. By using fluid-structure coupling numerical simulation, the evolution rule of fault conductivity under repeated disturbance of close double coal seam mining in 13 upper 09 and 13 lower 21 working faces is revealed. The results show that most of Wangzhuang faults in the natural state belong to the weak water conductivity area, the strong water conductivity area is mainly located at the elevation of-200 to -350 m in the north of the fault, and the water conductivity of Wangzhuang fault near the mining face is weak. The conductivity of Xiaonglou fault is zonal and gradually increases from deep to shallow. The conductivity of Xiaosonglou fault near the mining face is weak. There was no obvious disturbance in the fault bundle during the mining of 13 upper 09 working face. It is simulated that local disturbance failure occurs in the two faults of 13 upper 09 and 13 lower 21 working faces, but they are not connected with the surrounding rock failure area of the mining face, and the mining of the working face will not lead to “activate” water inrush.