To effectively restore the groundwater environment of the Shiping Mine (SPM) area, which is contaminated by acid mine drainage (AMD), a hydrogeochemical conceptual model was constructed based on groundwater chemistry and environmental stable isotopes. The contribution rate of various pollution sources in the groundwater environment was quantitatively analyzed using an optimized stable isotope mass balance model. A total of 68 groups of water samples were collected. The sampling period covered the dry, normal, and wet periods of a complete hydrological year. Samples were taken from rain, springs, mine drainage, tailing leachate, and surface water; and the detection and analysis indicators included 24 parameters, such as inorganic salts, heavy metals, and isotopes. A hydrogeochemical and statistical data analysis were performed. The main source of groundwater replenishment was found to be atmospheric precipitation, with the water-rock interaction of calcite and pyrite, and mining activities being the main controlling factors of hydrogeochemical processes. AMD significantly enhanced the dissolution of various minerals, and the detection rate of Zn, Cu, As, Cd, and Pb increased from 0–30% to 100% compared with groundwater in the upstream area of the mines. The optimized mass balance model results revealed that the contribution rates of upstream groundwater, mine water and leachate were 0.78–0.86, 0.08–0.18, and 0.04–0.06 for Heidong underground river, respectively; were 0.27–0.36, 0.62–0.68, and 0.03–0.05 for Tiantang underground river, respectively. Furthermore, based on the water balance analysis, 34–70% of the mine water was found to infiltrate directly through karst fissures and karst pipes and could not be collected at the mine entrance. AMD that directly infiltrated through runoff could easily be ignored due to the hidden migration path, which may cause remediation of groundwater environment to be remediated less effectively than expected
