Abstract: The diversified development of power energy structure brings great challenges to the stability control of the load frequency of interconnected power grids. In this paper, the load frequency control (LFC) model is established for the multi-hybrid power generation of the two-area interconnected power grids with the pumped storage power station. An LFC method of the linear active disturbance rejection controller (LADRC) is proposed, the parameters of which are obtained through the iterative optimization of particle swarm optimization (PSO). The proposed control method is simulated under both the pumping and generating conditions of the pumped storage power station considering different load disturbances in different areas of the interconnected power grid. The simulation results show that the LADRC controller optimized by PSO algorithm has stronger anti-disturbance capability and adaptability compared with the traditional PI controller, resulting in a better system dynamic stability.