Abstract: In order to cope with the complex sea conditions,improve the power capture efficiency of the direct-drive wave energy conversion system under irregular wave excitation,and reduce the influence of parameter uncertainty on the system,the hydrodynamic model and linear motor model were established,and a linear quadratic regulator method was proposed to design the system state feedback. The weight matrices were used to weigh the relationships between the system output power,the displacement and speed of the moving parts,and then the ideal electromagnetic force was calculated,so that the q-axis expected current could be obtained. According to the system perturbation mathematical model,the design of the controller was converted into standard H∞optimization problem,and the controller parameters were obtained by selecting the appropriate weight function to enhance the anti-interference of the system. The simulation results show that the proposed control strategy has higher output power and stronger robustness than PI control when the system model exists perturbations under the condition of constrained float displacement and speed,which can better cope with complex sea conditions,improve wave energy conversion efficiency.