Abstract: Based on the constructed ‘four-water’, namely the water ecology, water environment, water resources and water disaster, and socio-economic system dynamics model of the Yangtze River Economic Belt, 16 different development scenarios were set up by selecting parameters with sensitivity greater than 5%, and the different scenarios were simulated and evaluated. The results show that the difference in GDP per capita between different scenarios is small. The total wastewater, total COD and total NH3-N emissions are the largest when the socio-economic subsystem is developed as a priority and the water resources and water eco-environment subsystems are developed as a routine, with 4.37×104 million t, 2.56×106 t and 2.26×105 t, respectively, and the total wastewater, total COD and total NH3-N emissions are smallest when the socio-economic subsystem is developed as a routine and the water resources and eco-environment subsystems are developed as a priority, with 3.68×104 million t, 2.07×106 t and 1.82×105 t, respectively. Under the priority development scenario of the socio-economic and water disasters subsystems, the investment in flood and drought management increases. In the forecast year, the overall regional water security moves to a safer direction, and in the status quo simulation scenario (Scenario 1), the water security level can reach Level 4 in 2035. For priority development of a single subsystem, its impact on the overall water security of the region has a descending order: water eco-environment > water resources > water disasters > socio-economic. The model of conventional development of socio-economic subsystem and priority development of water resources, water eco-environment and water disasters subsystem is the optimal development model.