Abstract: To investigate the groundwater environmental quality and its eco-environmental effects of the Tai′an section in the Dawen River Basin, this study analyzes 190 sets of groundwater samples collected in 2024. Comprehensive methods including statistical analysis, Piper trilinear diagrams, Gibbs diagrams, and end-member diagrams were used to elucidate the hydrochemical characteristics and controlling factors. Groundwater quality assessment was conducted using both the Single Factor Method and Entropy-weighted Water Quality Index (EWQI) method in accordance with the Quality Standard for Groundwater (GB/T 14848-2017). The results show that: (1) Groundwater in the study area is weakly alkaline. The average total hardness (TH) and total dissolved solids (TDS) in pore water are 675.88 mg/L and 1234.28 mg/L, respectively, significantly higher than those in karst water (respectively 523.75 mg/L and 767.95 mg/L). The dominant hydrochemical type is HCO₃·SO₄-Ca, primarily controlled by the weathering of carbonate and silicate rocks. (2) EWQI evaluation results indicate that the proportion of excellent water quality in pore water and karst water is 51.25% and 84.55%, respectively. NO₃⁻ concentration in pore water (168.88 mg/L) is significantly higher than in karst water (81.02 mg/L), indicating a greater influences from agricultural and industrial activities. (3) Excessive groundwater extraction has led to a series of eco-environmental issues, including formation of regional depression cones, karst collapses, and water quality deterioration. The findings of this study indicate that human activities such as agricultural cultivation and industrial production are the primary factors leading to groundwater quality degradation. Concurrently, the over-extraction of groundwater resources has further exacerbated the spatial extent and severity of pollution.