Abstract: The prevention and control of coal mine water disaster is of great significance to ensure the safety of coal mine production and the stable supply of national energy. The water chemical analysis can identify the mine water source and judge the hydraulic connection of aquifers, providing the key scientific basis for the prevention and control of water damage. This study employs mathematical statistics, Durov, Gibbs, Pearson correlation analysis, and ion ratio coefficient methods to ascertain the hydrochemical characteristics of Caojiatan Coal Mine, subsequently analyzing their implications for effective water hazard prediction and control. The results indicate a progressive increase in the mass concentrations of K⁺+Na⁺, SO₄²⁻, Cl⁻, HCO₃⁻, and total dissolved solids (TDS) mass concentration in groundwater from shallow to deeper strata, accompanied by a gradual increase in pH; the hydrochemical type has undergone a significant change: the anionic hydrochemical type transitioned from HCO₃⁻ dominance to a mixed HCO₃⁻ and SO₄²⁻ type, while the cationic hydrochemical type evolved from a combination of Na⁺, Ca²⁺, and Mg²⁺ to a predominately Na⁺ type. This variation process reflects that the hydrochemical formation mechanism tends to be complex from shallow to deep strata. Further analysis reveals that cation exchange and leaching effects are continuously enhanced with the increase in groundwater depth; cation exchange contributed to elevated K⁺+Na⁺ mass concentrations in deeper groundwater, while leaching processes led to the oxidation of sulfide minerals within the coal seams, resulting in heightened SO₄²⁻ mass concentration. The differences of water chemical characteristics of different aquifers and the hydraulic connections between them are crucial for the accurate identification of mine water sources. At the same time, it is also helpful to determine the impact of the fall zone or water conduction fracture zone on the formation, and provide more accurate information and scientific basis for the prevention and control of coal mine water damage, so as to effectively ensure safety production.