Abstract: In this paper, a two-tier structure method is proposed for the coupling of multiple water sources allocation at the "plane" level with the optimal operation of the reservoir group at the "line-point" level for the river basins. Taking Yongding River basin for example, the rules of multi-sources-based water allocation and operation, including the rules for water supply and water diversion, multi-source water supply strategy and common water supply task allocation strategy are formulated, the model for multiple water sources allocation and optimal operation of reservoir group is established, and the operation schemes under the various scenarios of multi-source water supply and water demand in the basin as well as the water supply benefits from the optimal scheme are analyzed. The results show that: ① In the Yongding River basin, the scenario of combining multi-source water supply system consisting of the local water, water diverted from Yellow River, water from the South-to-North Water Diversion Project and the reclaimed water, with the water conservation is the optimal scheme. ② The guarantee rate of domestic water supply, industrial water supply and ecological water in Sanjiadian Section is greater than 99%, 97% and 96% respectively, with the guarantee rate of water supply in irrigation zones ranging between 76.7%—90.2% (except the upper reaches of Sanggan River). ③ The adoption of multi-source water supply and water conservation strategy can lead to significant improvement of the water supply efficiency for water users and abundance of the ecological water volume of Sanjiadian Section. The method described herein can serve as references for the study on the allocation of multiple water sources and the optimal operation of reservoir groups in a given river basin.