Comprehensive considering the main influencing factors of water resources carrying capacity, 16 quantitative indicators were selected from the four aspects: the water resources subsystem, social subsystems, economic subsystems, and ecological environment subsystems. In order to reduce the subjectivity level of analytic hierarchy process (AHP), the entropy weight method was used to modify the initial weight of evaluation index, the closeness was calculated based on the principle of ideal point method, and an evaluation model of water resources carrying capacity was constructed. This method was applied to the evaluation of the water resources carrying capacity in Jiangxi Province, and the results showed that the water resources carrying capacity of all cities in Jiangxi Province showed an increasing trend from 2011 to 2015. The geographical gap was obvious, especially, the cities of Nanchang, Ganzhou, Yichun, and Ji'an are with poor water resources carrying capacity, which has large population and rapid economic growths. This result is consistent with the actual situation of water resources carrying capacity in Jiangxi Province, and can guide the planning and utilization of water resources of Jiangxi Province and the belonging cities and the implementation and management of the "River chief system".