In this paper, under the conditions of pendular and longitudinal rocking motion, the motion models of float and oscillator are established by combining the collected basic parameters, and the pendular displacement and velocity and longitudinal angular displacement and velocity of float and oscillator are found for a time interval of 0. 2s within 40 wave periods. On this basis, the maximum output power and the corresponding optimal damping coefficients are studied when the damping coefficients of the linear and rotary dampers are constants in a specific interval, considering the vertical oscillation motion and the longitudinal rocking motion.