The manipulation of acoustic wave has great significance in engineering related to acoustic device design. Recent study reveals that acoustic metasurface can easily change the wave front by a periodic phase array composed of microunits, which provide us a branch approach in physical application. Here, we proposed a design of a 3D ultrathin acoustic carpet cloak based on acoustic metasurface in deep sub-wavelength range. The microunit of the metasur-face is constructed by two helmholtz resonators nested together and we can change the reflec-tion phase by adjusting the relative angle of the two helmholtz resonators. The carpet can completely conceal the object because the designed metasurface can compensate the phase distortion caused by the object. The operating frequency is about 1200Hz, numerical simula-tions show the carpet functions well in normal and small-angle oblique incidences. Moreover, the thickness of the metasurface is only approximately λ/19, so we can design the carpet cloak in expected shape with almost no increase in target size.
