Abstract: In order to construct an underground water reservoir for storing high-salinity water and achieve zero discharge through the treatment of highly mineralized mine water, it is necessary to accurately evaluate the permeability coefficient of the overlying strata aquifer in the goaf, taking the storage of high-salinity water in Lingxin Coal Mine as a research object, combined with rock mechanics and hydro-geological parameters, FLAC^3D finite difference software was used to conduct numerical simulations using Mohr-Coulomb constitutive model as a plastic yield criterion for rock and soil bodies. The development height of collapse zone and fracture zone during the mining process of L1614 working face in 14^# coal seam in No.1 mining area of Lingxin Coal Mine were determined. Based on numerical simulation results, porosity and permeability coefficients of collapse zone and fracture zone were calculated, the transverse and longitudinal distribution of permeability in the water-conducting fracture zone is analyzed. The results show that the horizontal distribution of porosity and permeability coefficient in caving zone of 14^# coal after mining is similar, showing a “basin” shape, with the largest near the coal wall and the smallest in the central part. The development height of the water-conducting fracture zone is 56 m, and that of the caving zone is 15 m. The longitudinal permeability coefficient of the water-conducting fracture zone increases gradually from top to bottom, ranging from 1.07×10⁻⁶ to 0.89 m/s, and the average permeability coefficient of the caving zone is 0.89 m/s.