The gradient SiNO coatings prepared by reactive sputtering were used as anti-reflection layers for Cr-CrNO (meaning Cr nanoparticles inside CrNO) cermets based spectral selective coatings. The compositions of both Cr-CrNO and SiNO can be facilely tuned by changing the gas flow of Ar, Ni and 02 in the process of deposition, which can correspondingly adjust the optical parameters of the coatings and induce the different absorption in visible range. The optimized configuration of coatings with three absorption layers and three anti-reflection layers demonstrated a high absorptance of 0.935 and low emittance of 0.056 at 82 °C. This kind of coating can be considered as a promising spectral selective material for the solar thermal collector applications.