Abstract: The successive completion of cascade hydraulic hubs in the middle and lower Hanjiang River has inevitably obstructed the natural river flow. To address the impaired hatching of drifting-egg fish species, this study quantifies the required eco-hydrological threshold indices for spawning using the ROC model, and combines the SWAT semi-distributed hydrological model and the MIKE11 one-dimensional hydrodynamic model to draft scheduling schemes under different scenarios. The results indicate that: ① the eco-hydrological thresholds for drifting-egg fish reproduction are a water level rise duration ≥3 days and a daily water level increase ≥0.3 m (P < 0.1, AUC>0.95). ② Model calculations determine the triggering conditions as: flow ≥1 200 m³/s at Huangzhuang Station (Hanjiang mainstem) and flow ≥100 m³/s at Dongpo Station (Tangbai River). Under three combined conditions-Tangbai River (Dongpo) ≥600 m³/s and Hanjiang (Huangzhuang) ≥2 100 m³/s, or Tangbai River (Dongpo) ≥300 m³/s and Hanjiang (Huangzhuang) ≥1 200 m³/s, or Tangbai River (Dongpo) ≥100 m³/s and Hanjiang (Huangzhuang) ≥1 200 m³/s-the coordinated open-discharge scheduling of the Yakou, Nianpanshan, and Xinglong hubs can satisfy the spawning and reproduction needs of the four major Chinese carps in the middle-lower Hanjiang River mainstream to varying degrees.