Abstract: In order to ensure the safe mining of coal seam under the influence of fault water, hydrogeological drilling, hydrogeological logging, pumping test, connectivity test, hydrochemistry and stable isotope analysis and other technical methods were adopted to comprehensively test the water conductivity of the north-south boundary fault in the Ganhe Mine Field. The results show that Xiatuanbai Fault and F1 Fault which are in the northern boundary of the mine field, as well as Xiazhangduan Fault in the south boundary of the mine field are all transtentional normal faults. There are obvious fracture zones in the ordovician limestone layers of the two faults, namely the large tectonic influence zone, and they have good fault conductivity; there are obvious hydraulic connectivities between Fengfeng Formation aquifers in both sides of the three boundary faults and so do Shangmajiagou Formation aquifers, this three faults are all partial water-conductive. The test results provide an important basis for the design of mining area as well as the prevention and control of water disasters.