Abstract: By taking cascade reservoirs on the middle Jinsha River as the research object and taking advantage of the fact that many aquatic organisms have high demands on flow and water level, this paper puts forward a method to meet the target ecological demands. A ecological connected water level is set at the ecological control section below the dam. A linkage response mechanism between ecological connected water level and ecological flow is formed by using the partially connected relationship between two adjacent reservoirs. The objective of this method is that the water level of the ecological control section meets the ecological connected water level. Through the joint regulation of adjacent cascades reservoirs, the control of ecological flow can be changed from a fixed value to a dynamic adjustment. Based on the Jinsha River fish spawning characteristics and demand for aquatic habitat, In this paper, main fish distributed in the tail of each reservoir are selected as target fish. The water depth, velocity and water temperature required for their survival and reproduction are the target ecological requirements. According to the water depth conditions required by the target fish during spawning period, a suitable inundation depth index and a ecological connected water level index are constructed at the tail stream reaches. Taking the two typical cases of the maximum length of the fish spawning reach and the nearest distance between suitable areas under the dam, the river length, starting and the ending points satisfying the suitable inundation depth are calculated. In addition, combined with the spawning velocity and water temperature requirements, ecological scheduling simulation is carried out, and the most suitable time for ecological scheduling is determined as late June, which can better play the ecological benefits of the cascade reservoirs. At last, the feasibility of flexible application of the method in different positions between adjacent cascades is demonstrated.