In this research, a two-dimension physical model experiment was conducted, which studied the influence of different porosity of the perforated arc slope plate on reflection coefficient of arc shaped wave absorbing structure, analyze the main factors of reflection under the different incident wave height and wave period condition. And on this basis, the structure was optimized which adopted a two layered composite form of structure. The optimal combination of porosity of two layered structure was obtained, the influence of wave height and wave period on reflection coefficient was studied by experiment.