Abstract: As water resources becoming increasingly scarce, sustainable use of water resources is a key problem for development of Hetao Irrigation District, China. The coupled model for conjunctive use of water resources was established by dynamically coupling numerical simulated model for groundwater with optimal allocation model of water resources. In the coupled model, groundwater level was adopted as a constraint condition and the optimal conjunctive utilization quantity of surface water and groundwater was set as the objective function. Finally, the coupled model was applied for optimizing allocation of the water resources of Hetao Irrigation District in 2020 and 2030. The results showed that the water from the Yellow River in 2020 and 2030 would reach 3.915×109 and 3.854×109 m3/a, respectively. Therefore, the surface water wonld be reduced to the national limited amount of 4.0×109 m3/a by adjusting wellcanal- irrigated area and industry structure appropriately. The research result can offer a valuable reference for efficiently using water resources and preventing the salinization for other similar regions.