Based on the Desantos spectral formalism, using the hybrid method that combines the numerical and approximate algorithms, the reconstruction problem for the one-dimensional rough surface is investigated. For the direct problem, the scattering data is obtained by the numerical algorithm—the method of moments (MOM). For the inverse problem, the profile of rough surface with different roughness is reconstructed by two approximate algorithms—the small perturbation approximation (SPA) and the Kirchhoff approximation (KA) combined with the method of moments. Taking the Gaussian rough surface for example, the numerical results of reconstructed rough surface with different roughness are presented for the hybrid method, and the data are compared and analyzed.