Here, a novel Au Wedge-enhanced Raman spectroscopy (WERS) substrate is proposed. The electric field enhancement factor and the effective mode field radius with varying geometry parameters are investigated. The proper excitation wavelength 633 nm is obtained. The practical application of WERS substrate is discussed. The Au WERS not only can provide a continuous extremely highly localized electric field as surface-enhanced Raman scattering (SERS) hotspots, but also can offer 10 orders of magnitude of SERS enhancement factor. The corresponding results reveal that WERS substrate will be widely applied in optics, biology, chemistry and other fields.