Given the complex interplay between climate change, human activities, and rising water demand, there is an urgent need for the implementation of long-term, sustainable water resource management strategies. The spatial-temporal mismatch between water resource distributions in river basins and the drivers of regional economic and social development constitutes a critical factor impacting sustainable development. Based on the Shared Socioeconomic Pathway (SSP) framework and the STIRPAT model, this study proposes a method for predicting water demand in agriculture, industry, domestic, and ecological sectors of river basins under SSP scenarios. Historical data from the Mintuo River Basin were analyzed to establish an integrated index framework for water demand driving factors, and extended SSP scenarios incorporating water components were defined. The results show that there are significant differences in water demand predictions for the period 2025 to 2050 under different SSP scenarios. The sustainable development pathway (SSP1) yields the most favorable outcomes, while in the SSP2-SSP5 scenario, the basin may face unsustainable water pressure. This study applies the SSP framework to long-term water demand management in river basins, providing a scientific basis for analyzing future regional water demand and developing sustainable water use plans consistent with future socioeconomic development trajectories, thereby supporting the sustainable development of water resources in the river basin.