Abstract: In this study, an evaluation approach based on the connection number and Lorenz curve was proposed to investigate the quantitative impact of each sub-region on the spatial equilibrium of the water resources in the entire region during the evaluation process. The Lorentz curves connecting the total amount of water resources with cultivated land area, population and the secondary industry GDP were constructed, respectively, where the evaluation sample value based on the vertical distance was calculated. Meanwhile, the connection number of the sample was calculated via the set pair analysis, followed by the determination of equilibrium level and the comparison with the Gini coefficient method. Application of the proposed approach to Anhui Province of 2011—2018 revealed that the overall spatial imbalance status existed between the total amount of water resources and cultivated land area, population size along with the secondary industry GDP, respectively. In contrast, the level of equilibrium between the total amount of water resource and cultivated land area, population size has been ameliorated, while the equilibrium status of the total amount of water resource and the GDP of secondary industry remained serious that require further improvement. With the quantitative estimations, it offers a novel and effective way for estimating the spatial equilibrium of regional water resources.