The waste slag produced from antimony mining contains a large amount of toxic heavy metals, which pose serious risks to the ecological environment and human health. This study selected antimony mining area waste slag and leachate as research subjects, applying the geoaccumulation index method, Nemerow pollution index method, potential ecological risk index method, and health risk assessment model for risk evaluation. The results indicate that the average values of Pb, As, Cd, and Sb in the waste slag exceed the soil background values of Hunan Province. In the leachate, Sb significantly exceeds the standard limits, with 67% of samples exceeding the standard threshold. Spatially, As and Sb show a trend of decreasing from south to north, while the spatial distribution of other heavy metals varies greatly. The pollution index assessment method shows severe contamination of Sb and Cd in the waste slag, with leachate primarily affected by Sb pollution. The potential ecological risk index method indicates that heavy metals in both waste slag and leachate pose extremely high and high ecological risks, respectively. The health risk assessment indicates that drinking water is the primary pathway contributing to health risks, with significant non-carcinogenic risks posed by Sb and As. Carcinogenic risks for Cr and As exceeded the potential carcinogenic risk limits for two populations and two pathways. The results of this study provide a scientific basis for the prevention and control of heavy metal pollution in water resources in antimony mining areas.