<p>Under the dual imperatives of global energy transition and carbon neutrality goals, hydropower scheduling is accelerating toward multi-energy, complementary dispatch systems. However, the coordinated operation of hydropower, wind, and solar power induces short-period fluctuations in reservoir water level and downstream release flow, which affect fish habitats to varying degrees. This study uses the Yangqu Hydropower Station on the Upper Yellow River as a case study to develop a multi-objective eco-coordinated dispatch model that links residual load fluctuation with fish habitat area. By coupling a two-dimensional hydrodynamic model with a fish habitat suitability model, we quantitatively assess the impacts of different hydropower-wind-solar dispatch scenarios on fish habitats. Results show that, under the eco-coordinated dispatch scenario, residual load fluctuations exhibit a significant trade-off relationship with both the fluctuating tailwater return zone and downstream riverine fish habitats; the tailwater return zone and downstream habitats generally display a synergistic relationship, except in low-flow years and at smaller target levels, where a moderate trade-off emerges. Habitat suitability varies substantially across different water-year types under the studied dispatch schemes. While alternative dispatch strategies have limited effects on residual load fluctuations and tailwater return zone habitats, they markedly influence downstream riverine habitats. Accordingly, selecting an appropriate ecological dispatch scheme can enhance downstream riverine habitat suitability. These findings provide theoretical support for the coordinated development of hydropower scheduling and ecological protection in the Upper Yellow River.</p>