<p>Fluoride-enriched geothermal resources have the potential risks for human health, which may cause dental fluorosis and bone fluorosis. Previous research has predominantly focused on the hydrochemical characteristics of high-fluoride groundwater in the North China Plain (NCP), with limited attention given to the evolution of fluoride-enriched geothermal groundwater. This study, utilizing a dataset of major ion concentrations, δD, and δ¹⁸O from 45 samples, aims to investigate the hydrochemistry, evolution, and genetic mechanisms of fluoride-enriched geothermal groundwater in southern NCP. Our findings indicate that the geothermal groundwater originates from precipitation in the Taihangshan area, with a recharge elevation of 1415 ~ 1838 m. After deep circulation at depths of 3556 ~ 4135 m and heating by a geothermal reservoir at 150 ~ 170 °C, the groundwater mixes with shallow cold groundwater during upwelling, incorporating a proportion of 58 ~ 93%. The hydrological evolution process of fluoride-enriched geothermal groundwater is primarily driven by water–rock interactions and the dissolution of fluoride-enriched minerals, while also being influenced by the alkaline groundwater environment and cation exchange interactions. Based on these analyses, a conceptual model of the evolution of fluoride-enriched geothermal groundwater in the NCP is proposed. Health risk assessment results reveal that children are at a higher health risk from fluoride—enriched geothermal groundwater compared to adult females and males.</p>