Abstract: Under the vision of the "dual carbon" goal, it is urgent to accelerate the development of clean energy and build a green and lowcarbon new power system. However, clean energy represented by solar energy is affected by natural factors and has strong volatility and randomness, making it difficult to consume in large quantities through grid connection. Therefore, considering the long construction period and significant impact of natural inflow on the regulation performance of traditional hydropower, adding reversible units to traditional hydropower units to form a hybrid pumped storage power station increases its hydropower regulation capacity, and can operate in conjunction with photovoltaic power stations to suppress the volatility of photovoltaic power generation and promote grid connected consumption. To explore the operation mode of the water solar storage complementary power generation system with hybrid pumped storage power stations under a large number of photovoltaic grid connections, this paper constructs a daily optimization scheduling model with the optimal source load matching as the objective function. The solution strategy is nested in multiple time scales from medium term to short one, using medium and long-term time scale calculation results as short-term time scale calculation boundary conditions, and the stepwise optimization algorithm and particle swarm optimization algorithm are used to solve the system operation mode under different incoming water and photovoltaic output scenarios.The results indicate that under the premise of different incoming water and different photovoltaic output processes, hybrid pumped storage power plants can adopt different operating conditions, forming a “concave” shaped output with traditional hydropower and complementing the photovoltaic output, which can not only promote photovoltaic grid connection and consumption, but also meet the load demand of the power grid. In addition, under different typical days, the daily water level fluctuations of the upper and lower reservoirs of hybrid pumped storage power stations show a trend of “discharging first and then storing” in the upper reservoir and "storing first and then discharging" in the lower reservoir. The research results provide reference for the operation mode of hybrid pumped storage power plants with a large amount of photovoltaic stations connected to the grid.