Abstract: Aiming at the problem that the coupling coordination analysis of the provincial scale of the Yangtze River Economic Belt is difficult to accurately guide the fine development of local areas, this paper sinks the research scale to the district and county level. Taking the districts of Nanjing as the research object, the coupling coordination model of water resources-social economy-ecological environment system is constructed, and the XGBoost-SHAP model is further used to explore the key driving factors and interaction effects of the coupling coordination degree of each district in Nanjing. The results show that : ①From 2011 to 2023, the comprehensive development level of each district in Nanjing is on the rise as a whole. ②Although there is no high-quality coordination, the overall trend is good. ③The key factors affecting the coupling coordination degree of the system in each district of Nanjing are different. Therefore, according to the development stage of each district, the key factors of system coupling and coordination and the interaction effects between them, it can provide a more accurate scientific basis for optimizing resource allocation, balancing economic development and protecting ecological environment in each district of Nanjing. At the same time, the XGBoost-SHAP model also provides a new direction for studying the regional coordinated development.