Abstract: The joint operation of reservoir groups in the upper reaches of Changjiang River has created favorable conditions for further raising the flood control compensation level of Three Gorges Reservoir(TGR) to Chenglingji Area after the construction and operation of Wudongde Reservoir and Baihetan Reservoir.To raise the controlled water level of Three Gorges Reservoir carrying out compensation dispatch to Chenglingji Area, aiming at the operation conditions of the flood control storage capacity of the four reservoirs in the lower Jinsha River, as well as the design floods of different frequencies in different typical years at the Three Gorges dam site, risk analysis on Jingjiang Reach and reservoir backwater are performed, so an equal proportional and graded storage mode for cascade reservoirs on lower Jinsha River assisting TGR is proposed.Moreover, under the premise that the flood control risks of Jingjiang Reach and reservoir backwater are controllable, an optimal scheme for flood control compensation level with different flood control capacities of cascade reservoirs in the lower reaches of Jinsha River is present, and the equivalent relationship between the reserved flood control capacity is provided.The research results demonstrated that the proposed equal proportion graded storage mode integrates the two modes of storing quantity and peak shaving, effectively using the flood control storage capacity of cascade reservoirs in the lower Jinsha River with the best effect.The proposed optimal scheme has better flood control and disaster reduction effects, which can further reduce the excess flood volume in the middle and lower reaches of the Changjiang River.The research results can provide technical support for the actual Changjiang River flood control and decision-making reference.