Abstract: The inflow of reservoirs such as Yakou Reservoir in the middle and lower reaches of the Hanjiang River is affected by the scheduling plans of upstream controlling reservoirs such as Danjiangkou Reservoir.Therefor its initial water storage is constrained by various factors, including engineering safety, reservoir bank safety, reservoir immersion, water use of production, living and ecology, Xinglong Project navigation, and the risk of water bloom.A coordinated initial water storage plan, taking into account inflow and water use both upstream and downstream, is crucial.This article takes the Yakou Project as an example and analyzes the various constraints on its initial water storage, based on the characteristics of the Hanjiang River Basin.It also calculates the inflow during the water storage period, which is affected by upstream controlling reservoirs, proposes a two-stage water storage model for reservoirs considering multiple constraints, and formulates an initial storage plan.The results indicate that there is little difference in the duration of water storage for the Yakou Project under different water storage schemes.The initial water storage has little impact on downstream production, living, ecology, and navigation water use, but attention should be paid to the impact of operating at a high water level for long periods on engineering safety, flood control safety, and reservoir bank safety.This method can provide a reference for the initial water storage of reservoirs in similar situations.