Abstract: Groundwater in mining areas serves as a critical water source for production, domestic use, and ecological sustainability, with its quality directly impacting regional sustainable development. As a newly planned large-scale integrated mining area under national strategic development, the Xinjie Taigemiao Mining Area is situated in a typical arid to semi-arid region characterized by complex hydrogeochemical conditions. Notably, groundwater in this area exhibits a significant trend of fluoride enrichment, posing potential challenges to water security and environmental health management. To address the unclear contamination characteristics and genetic mechanisms of fluoride in groundwater of the Xinjie Taigemiao Mining Area, methods including correlation analysis, hydrogeochemical modeling, and principal component analysis (PCA) were employed to investigate the spatial distribution patterns and underlying mechanisms of fluoride enrichment. The results revealed that the overall ion concentrations in groundwater exhibited fluctuating increases with aquifer depth, accompanied by a shift in hydrochemical type from HCO₃−Ca·Na to Cl·SO₄−Na. Fluoride concentrations displayed a latitudinal distribution pattern (higher in the north and lower in the south) and a vertical enrichment trend, with average concentrations exceeding 4.1 mg/L in the middle-lower Yan’an Formation aquifers at depths greater than 700 m. Based on Gibbs diagrams, ionic ratios, and PCA, fluoride enrichment was primarily attributed to the dissolution of fluorine-bearing minerals (e.g., fluorite), while evaporation concentration, dissolution of silicates and halite, and positive cation exchange were identified as contributing factors. Hydrogeochemical simulations further demonstrated that the dissolution of key minerals (gypsum, halite, quartz, dolomite, and fluorite) in the vertical profile from the Zhidan Group to the Yan’an Formation released 5.43×10⁻³, 18.18×10⁻³, 0.36×10⁻³, 0.11×10⁻³ and 0.32×10⁻³ mmol/L of ions into groundwater, respectively. These processes promoted the progressive release and accumulation of fluoride with increasing stratigraphic depth, resulting in distinct vertical spatial distribution characteristics.