The interaction between water resources, economy, and ecology significantly influences regional security and stability. This study developed an index system for assessing the coupling of water resources, economy, and ecology in Shanxi Province. Subsequently, a coupling coordination degree model for water resources, economy, and ecology was established to assess and analyze the coupling coordination levels. Additionally, the study employed a grey correlation analysis to investigate the impact of 21 indicators on the system's coupling coordination. A system dynamics simulation model was then constructed to forecast various coupling coordination scenarios up to 2035. Key findings included: (1) An overall upward trend in the comprehensive evaluation index of water resources, economy, and ecology. (2) Significant developmental disparities among the eleven cities in Shanxi Province, with some cities showing a decline in 2015. (3) The economic subsystem indicators in the water resources-economy-ecology model had a 34.02% correlation, exerting a marginally greater impact on the system's coupling coordination than other subsystems, with GDP per capita being the most influential indicator. (4) Scenario simulations predict that the highest level of coupling coordination, reaching a coupling coordination degree of 0.94, will be achieved in 2035 under Scenario 5(pursuing comprehensive development). This study elucidates the interrelationship between water resources, the economy, and the ecosystem in Shanxi Province, and proposes a programme for adjusting indicators to support future sustainable development in the region.