Abstract: The increase of mining depth and the large-scale mining of coal seam are affecting the structure of underground water system in mining area. The study of chemical characteristics of underground water and its evolution law is of great significance to the safe mining of coal mine. Taking different aquifers groundwater of Yangliu Coal Mine in Huaibei Mining area of Anhui province as the research object, this paper systematically analyzes the chemical characteristics and evolution mechanism of groundwater in Yangliu Coal Mine by means of mathematical statistical analysis and Piper three-line graph. The results show that, the aquifers in the study area are weakly alkaline as a whole, the fourth aquifer of Cenozoic is dominated by Na⁺+K⁺ and SO₄²⁻, the fractured sandstone aquifer of Permian is mainly controlled by Na⁺+K⁺ and HCO₃⁻, and the major affecting ions in the Taiyuan Formation and Ordovician limestone aquifers are Ca²⁺ and SO₄²⁻. There are some differences in hydrochemical types among these aquifers. SO₄·HCO₃−Na·Ca and HCO₃−Na·Ca types dominate the fourth aquifer Cenozoic, HCO₃·Cl−Na type dominates the sandstone fissure aquifer, and SO₄−Mg·Ca·Na type dominates the Taiyuan Formation 1-4 ash aquifers. The Ordovician limestone aquifer is dominated by SO₄−Ca·Mg type and SO₄·HCO₃−Ca·Mg type. Each aquifer in the mining area is mainly affected by rock weathering and evaporation and concentration. Salt rock and silicate karst in the water are deconstructed into the main source of Na⁺+K⁺, and sulfate and carbonate karst hydrolysis are the main sources of Ca²⁺ and Mg²⁺. Besides carbonate dissolution, HCO₃⁻ is also controlled by desulphurization acid. SO₄²⁻ is mainly derived from sulfate dissolution and pyrite oxidation. The leaching and human activities contribute more to the chemical composition of groundwater.