Abstract: Longnan City, a typical region in the Qinba Mountains of northwest China, has over 70% of its population relying on groundwater as their primary drinking water source. To ensure local residents' drinking water safety, a systematic assessment was conducted on groundwater quality characteristics and health risks at 205 water sources in the area. The study examined 16 key indicators including pH, TDS, TH, Cl⁻, \mathrmSO_4^2- , COD, As, Cr, and Cd, combined with the Water Quality Index (WQI) and Health Risk Assessment (HRA) models for comprehensive evaluation. The results indicated that water parameters generally showed a distribution pattern with dense low-concentration samples and sparse high-concentration samples, while localized abnormal high values were observed for sulfate and chloride. The hydrochemical process was dominated by mineral dissolution, with some areas potentially facing industrial pollution risks from electroplating and non-ferrous metal smelting. While the WQI assessment revealed overall excellent water quality, significant spatial heterogeneity existed across Longnan City. Poor-quality water areas were concentrated in central-eastern regions, while better-quality areas were widely distributed in mountainous and hilly western and southern regions. The health risk assessment model showed that non-carcinogenic risks for individual elements were all below 1, with cumulative non-carcinogenic and carcinogenic risks remaining within acceptable ranges. High-risk areas were mainly found in parts of eastern and central Longnan City, while low-risk zones primarily covered western and southern mountainous and hilly regions. These findings indicate that the groundwater in Longnan City is generally safe. However, it is essential to trace the sources of localized high-concentration areas, strictly control agricultural pollution, investigate potential industrial risks, and enhance monitoring of high-risk indicators such as F⁻and Hg to ensure the safety of residents' drinking water.