With the emergence of global environmental and climate issues, the advantages of clean energy, such as hydropower, wind and solar energy are highlighted. In a power system with high penetration of hydropower, the cascaded hydropower station needs to serve the peak load and the base load at the same time. How to coordinate the peak-shaving optimization operation of the cascaded hydropower station and the uncertain wind-photovoltaic power stations is of great significance. This paper considers the uncertainty of the wind and photovoltaic power stations, and proposes a coordinated peak-shaving optimization operation strategy of cascaded hydropower stations and wind photovoltaic power stations. On one hand, the adjustment capability of the cascaded hydropower stations is utilized to increase the accommodating generation of the wind-photovoltaic power stations, and the load fluctuation is minimized as much as possible to reduce the peaking pressure of the thermal power units. On the other hand, the nonlinear water-to-power conversion function is linearized to facilitate the model solution. The simulation analysis results of a system with high penetration of hydropower verifies the correctness and effectiveness of the proposed optimization strategy.