An integrated wave energy extraction (IWEE) system consisting of a heaving buoy and a perforated wall was investigated using the linear potential flow theory. The methods for the separation of variables and eigenfunction expansion matching were adopted to determine the spatial velocity potentials. The model was verified through wave energy flux conservation and a flume experiment. Subsequently, a comparison and a parametric study was carried out to investigate the hydrodynamic performance of the IWEE system. The introduction of the perforated wall increased the maximum capture width ratio of the buoy and significantly reduced the transmitted coefficient. Compared with the IWEE system with a solid rear wall, the proposed system mainly generated a smaller reflection coefficient and the buoy endured a smaller horizontal wave force as well. The frequency where the radiation damping equals zero was not found for the buoy of the proposed system. The wave capture efficiency and wave attenuation performance could be enhanced by properly setting the geometrical parameters. Furthermore, the wave energy captured and dissipated by the proposed IWEE system was much greater than that dissipated by an isolated perforated wall, which indicates that the system is feasible in terms of energy consumption.