Abstract: The conflict between water resources, ecological environment, and economic development has become increasingly prominent. Coordinating watershed economic development with water resources and ecological environments is a critical task for achieving sustainable socio-economic development in China. This study conducts a comprehensive evaluation of the coupled water resources-water environment-economic society (WEE) system in the Muwen River Basin, aiming to promote their coordinated development and provide technical support for decision-making in basin planning. By constructing a multidimensional coupling evaluation system and integrating Moran’s I index with the PSO-SVR model, this research reveals the interactive evolution patterns of the WEE system in the Muwen River Basin in 2025, 2030, 2035. The results indicate: (1) Temporal evolution exhibits a declining trend characterized by "high coordination (pre-2012) → moderate coordination (2013–2016) → low coordination (2017) → moderate coordination (2019–2020),". (2) In spatial terms, areas with higher indices for the water-resource, water-environment, and socio-economic sub-systems are clustered in densely urbanized zones; the overall coordination of the coupled system peaked in 2015 and declined across all regions by 2020. (3) The obstacle-degree analysis reveals that chemical-fertilizer application intensity is the dominant influencing factor, and the most significant obstacles are largely concentrated within the water-environment sub-system. (4) Scenario predictions suggest that the water resources index will rise to 0.689 by 2035, while the water environment system will undergo a U-shaped restoration cycle. These findings not only provide direct technical guidance for sustainable development in the Muwen River Basin but also offer insights for green watershed governance.