In order to analyze the damage range of overburden after mining in Z220981 working face of Zastoqi Mine, the underground pressure water test method was used to measure and analyze the damage range after mining. Two water pressure test boreholes No. 1 and No. 2, angle of 56 °and 62 °respectively, by sorting out two drilling test data and judging the boundary between caving zone and fissure zone when the drilling depth was 15-20 m from the measured data of No. 1 drilling hole, it was concluded that there was a boundary between fissure zone and complete subsidence zone when the caving zone was within 12.45 m to 16.6 m and the drilling depth was between 60 m and 65 m, and the upper limit of fissure zone was about 49.80 m to 53.95 m. Drilling can be judged by the measured data of No. 2 drilling hole. There was a boundary between the caving zone and the fissure zone when the hole depth was 10 m to 15 m. It was concluded that the caving zone is in the range of 8.8 m to 13.2 m, and there is a boundary between the fissure zone and the complete subsidence zone when the hole depth was 65 m to 70 m. It was concluded that the upper limit of the fissure zone was between 57.2 m and 61.6 m. By synthesizing the data of two boreholes, it was concluded that after strip mining, the aquifer would not be affected by the water conducting fracture zone, ensuring safe mining.