This paper mainly focuses on the in-depth study of the energy conversion efficiency of the built-in PTO-type wave energy device and explores the dynamic response and maximum power output of the device by using theoretical analysis and MATLAB simulation model. Firstly, the study determines the vertical oscillation displacement and velocity of the float and oscillator under different wave conditions and the longitudinal swing angular displacement and angular velocity, which reveals the basic characteristics of the dynamic response; secondly, the average output power of the PTO system is improved by constructing a mathematical model and optimizing the damping coefficients of the linear and rotary dampers; lastly, the experimental results validate the validity of the perturbation observation method of the hierarchical adjusting step size for power tracking. Finally, the experimental results verify the effectiveness of the perturbation observation method with graded adjustment step for power tracking, which clarifies that the maximum output power of the system under different damping coefficients can be up to 754625.1285w, which provides a new theoretical basis and technological path for the development of wave energy conversion technology.