This paper proposes a method to design the optimal hybrid robust controller considering the norm weight in the optimization process and applies it to the load frequency control of the microgrid, including wind turbine, photovoltaic and small hydropower. Based on the established microgrid load frequency model, the controller optimization takes the minimum square integral of the frequency fluctuation of the system as the optimization objective, integrates the robust performance expressed by the two norms, and designs an optimal hybrid robust controller. The particle swarm gravitation search algorithm based on contraction coefficient (CPSOGSA) is used to optimize the relevant weighting matrix reflecting the system performance weight value, and output robust performance. The controller can achieve optimization under constraint conditions. The simulation results show that the proposed method has better dynamic performance for the load frequency of the microgrid under external disturbance and system internal parameter disturbance. This work is supported by the National Natural Science Foundation of China (No. 51869007)