A measuremant method of thickness and refractive index of film grown on the strong absorption substrate is proposed. A thin metal layer is deposited on a transparent film which is grown on a strong absorption substrate. As a result, an analogue waveguide configuration of metal-transparent film-absorption substrate, which can accommodate a series of resonant modes, is formed due to a bigger reflectivity on the absorption substrate for the small angle of incidence. Based on the free-space coupling technique and the eigenvalue equation of the resonant modes derived by the standard electromagnetic field theory, the thickness and refractive index of the transparent film are simultaneously determined with a relative error of 1×10-3. The proposed method is simple and reliable, and can be used for the film with different refractive indexes.