This study is based on the field investigation and analysis of groundwater samples. It used single-index evaluation and comprehensive evaluation methods to evaluate the groundwater quality of the Nanyang-Xiangyang basin: The Ⅱ-III type shallow groundwater accounted for 26.27% in the Nanyang-Xiangyang basin; the IV type shallow groundwater accounted for 43.22%, and the V type shallow groundwater accounted for 30.51%. The primary indices affected by geological forces and the secondary indices affected by human activities jointly influenced the groundwater quality of Nanyang-Xiangyang basin. Human living and production, oil extraction, and mining activities were the main factors affecting the quality of groundwater in the area. In this study, the main factors influencing the quality of groundwater were identified through the calculation of "single index’s contribution rate to Ⅵ-Ⅴ type groundwater" and "human activities influence degree". The single index with the largest contribution rate to Ⅵ-Ⅴ type groundwater was nitrate, which contributed 56.32%. It was followed by total hardness, iron, and manganese. The human activities influence degree to the shallow groundwater in Nanyang-Xiangyang basin was 54.87%, and the main impact index was the "three nitrogens".