Abstract: Fluoride ion (F⁻) is prevalent in groundwater, and long-term consumption of highly fluoridated groundwater (F⁻＞1.0 mg/L) will pose a serious threat to human health. Highly fluoridated groundwater in Heze was selected as the research object, and statistical analysis, graphical method, geographic detector and health risk assessment model were comprehensively applied to analyse the characteristics of the spatial and temporal distribution of F⁻ concentration in groundwater and the dominant factors, to explore the causes of F⁻ enrichment in groundwater, and to evaluate the health risk of F⁻ to human beings through drinking water pathway. The results showed that the F⁻concentrations in groundwater during the abundant and depleted periods ranged from 0.33 to 4.61 mg/L (mean 1.89 mg/L) and from 0.10 to 4.68 mg/L (mean 2.11 mg/L), respectively; 66% of the samples during the abundant period and 78% during the depleted period had F⁻ concentrations exceeding 1.0 mg/L; and the distribution of F⁻concentrations in groundwater showed an overall pattern of high in the southeast and low in the northwest. F⁻concentration distribution in groundwater was high in the southeast and low in the northwest; annual rainfall was the dominant factor influencing the spatial and temporal variability of fluoride ion concentration; weakly alkaline environment, dissolution and precipitation of minerals (fluorite, dolomite, calcite), cation exchange and evaporation were the main processes of F⁻enrichment in groundwater; it was found through the results of the health risk evaluation that the health risk of F⁻ through drinking water pathway was higher in the abundant period than that of the dry period for both adults and children, and the hazard to children was higher than that to adults in the dry period, and the risk to children was higher than that to adults in the dry period. The health risk assessment results showed that the health risk of F⁻ through drinking water pathway was higher for adults and children in the abundant water period than in the dry water period, and the harm to children was higher than that to adults. The results of the study provide a certain scientific basis for the utilisation of groundwater resources in Heze.