Abstract: In view of the conflict between the development of hydropower and ecological environment protection in the joint optimal operation of reservoir groups, taking the Jialing River Basin as an example, a multi-objective joint optimal operation model of reservoir systems was constructed, to maximize power generation of reservoir systems and discharge most appropriate ecological flow and minimize water shortage of Wusheng section.By PA-DDS algorithm, the model was solved and the Pareto optimal solutions were obtained.The replacement ratio was introduced to quantitatively analyze the competition and coordination relationship between power generation target and ecological target under different water inflow conditions, and the fuzzy optimization method was adopted to seek the optimal balanced dispatching strategy.The results showed that under different inflow conditions, there was a competition between the power generation target and the ecological target, and the contradiction was mainly reflected in the non-flood season.Adopting balanced dispatching strategy can not only guarantee the power generation efficiency, but also fully meet the minimum ecological water demand and basically meet the appropriate ecological water demand.The research results can provide technical support for the joint operation mode of eco-friendly reservoirs in Jialing River Basin.