<p>The limited studies were performed to clarify the hydrogeochemical processes and mechanisms of subsidence pools in coal mining area. In this study, the surface water samples were collected from subsidence pools in coal mining area of Northern Anhui Province, China. Based on the determination on physicochemical parameters, the statistical analysis, Piper diagram, Gibbs model diagram, ion ratio methods, and the self-organizing map were applied to interpret the hydrochemical characteristics and genesis. The results showed that the dominance order of main cations was Na⁺ &gt; Mg²⁺ &gt; Ca²⁺ &gt; K⁺, with the average anionic concentrations followed the order of HCO₃⁻ &gt; SO₄²⁻ &gt; Cl⁻ &gt; NO₃⁻. The hydrochemical types from the pools subsided for more than years were HCO₃-Na type, while the subsidence pools formed in less than 20&#xa0;years mainly presented SO₄·Cl-Na type. The weathering and dissolution of silicate rock and halite controlled the hydrogeochemical processes, but the contribution of evaporite minerals cannot be excluded in study area. The dominate mechanism was rock weathering, when the positive ion exchange of Ca²⁺ and Mg²⁺ replacing Na⁺ and K⁺ and coal mining activities had some effect on the hydrochemical process. Na⁺ and HCO₃⁻ mainly came from the weathering and dissolution of sodium-containing silicate minerals, when the dissolution of silicate minerals and evaporate minerals was main sources of Ca²⁺ and Mg²⁺. SO₄²⁻mainly derived from the gypsum dissolution, along with its high SO₄²⁻ concentration resulting from human mining activities. This study will provide the effective information for protecting water resources in coal mining areas.</p>