The traditional control method for maximum power capture strategy under random sea wave environment has not considered the system model nonlinearity, system loss, and system physical constraints. Therefore, a power optimization scheme for wave power system based on economic model predictive control is proposed. The proton line spectrum estimation method was used to fit the wave radiation force, and a mathematical model of the wave power generation system was established based on the hydrodynamic equation and the state equation of the machine. Considering the power loss of the machine, taking the maximum wave energy capture as the objective function, the optimal electromagnetic force that meets the constraints of the system is solved. The current vector and spatial pulse width modulation strategies are used to achieve maximum wave energy capture. The simulation results show that the method proposed has fast response speed and strong robustness, which can enable the wave energy conversion device to operate within a reasonable range, improve the wave energy utilization rate, and reduce the body strain.