Abstract: Through the methods of hydrogeological drilling, isotope technology and water level measurement, the paper analyzes the sources of water inrush in the West Open-Pit Coal Mine and evaluates the water recharge from each source, which provides scientific basis for geological hazard assessment and pit planning and utilization of the mine. The results show that the west open-pit is a regional groundwater gathering area, with runoff from the surrounding groundwater. The total amount of water flowing to open-pit from surrounding areas is 2 477.8×10⁴ m³/a, mainly from the lateral recharge of Hunhe River through the Quaternary aquifer in the north slope of the open-pit, and atmospheric precipitation recharge, among which the water inflow from Hunhe River is about 1115.7×10⁴ m³/a, accounting for 45.0%, and the water amount of atmospheric precipitation directly falling into the mine is about 997.8×10⁴ m³/a, taking up about 40.3%. The water supply of Guchengzi River through the west slope of the open-pit is about 177.9×10⁴ m³/a, while that of groundwater supplied by lateral runoff from the paleochannels of Yangbai River and Liushan River in the south slope of the open-pit is about 186.4×10⁴ m³/a. The east slope is close to draining under the influence of East Open-Pit Mine.