Abstract: There is a mutual feeding mechanism among water resources, economic society and ecological environment, which constitutes the water resources complex system. Exploring the coupling status of the composite system and analyzing the main influencing factors are of key significance to promoting the sustainable and coordinated development of the system in the future. Combined with the current characteristics and problems of Hunan Province’s water resources status, economic society development and ecological environmental protection, a coupled and coordinated evaluation index system of water resources, economic society and ecological environment system containing 28 indicators is established by using quantitative data analysis method, and the weight of indicators are determined by AHP-CRITIC combination weighting method based on game theory. The spatio-temporal evolution characteristics of the coupling coordination of the water resources, economic society and ecological environment system in 14 administrative regions of Hunan Province during 2005-2020 are evaluated through the coupling coordination model, and the obstacle degree analysis model is used to diagnose and analyze the influencing factors of coupling coordination degree of composite system. The results show that in recent years, the comprehensive evaluation index of water resources and ecological environment subsystems in Hunan Province has rebounded, and the overall comprehensive evaluation index of the composite system has shown an insignificant upward trend, and its change process is mainly affected by the evaluation index of water resources subsystem. At present, the coupling degree among the three subsystems is in a high level coupling state, and other regions except Xiangtan City are in a coordinated development state. The overall coupling and coordination degree of the system is basically stable at the intermediate coordination level, and generally develops in a good direction. According to the development and changing trend of the three subsystems and the identification of obstacle factors of the indicators, water resources and economic society have become the main factors affecting the future sustainable development of Hunan Province, which is the key control direction to solve the existing problems of Hunan Province and realize the future sustainable and coordinated development.