Abstract: The joint operation of reservoirs brings huge economic and social benefits, and also has a lot of impacts on the river ecology. In order to improve the comprehensive benefits of power generation, navigation, ecology and Qingshitan Reservoir storage of the joint operation of Lijiang parallel reservoirs, the multi-objective parallel reservoirs operation model considering ecological flow requirement of fish is developed. The model is optimized by Non-Dominated Sorted Genetic Algorithm-Ⅲ. The results show that: (1) Compared with regular operation, parallel reservoirs optimal operation can ensure the benefit of power generation, and guarantee the benefit of navigation and ecology at the same time. (2) The constructed multi-objective parallel reservoir ecological operation model maintains the rate of ecological flow requirement above 47% in dry, normal and wet years. In particular, the ecological demand of fish during the winter, spawning and breeding periods is guaranteed. (3) The implementation of joint operation of the Lijiang parallel reservoirs can alleviate the pressure of water supply of Qingshitan Reservoir, and increase the reservoir storage in dry and wet years by 22.26×10⁶ m³ and 24.55×10⁶ m³, respectively. This study can provide a reference for multi-objective ecological operation of parallel reservoirs.