The invention relates to a selective solar energy absorber and a manufacturing method thereof. A later system comprises an absorber layer (2) arranged on a substrate (1) and a transparent low-refractive-index dielectric covering layer (6) arranged on the absorber layer (2). The absorber layer is a mixed layer (4) composed of a transparent high-refractive-index dielectric material and an absorbing material. The transparent material contains silicon nitride, silicon aluminum nitride or optically-equivalent aluminum nitride as an essential component. The absorbing material contains nitride of chromium or its alloy, or nitride, oxide or oxynitride of other metal or its alloy as an essential component. The selective solar energy absorber is chromic oxide-free, and compared with the prior art, the selective solar energy absorber is not complex in configuration, so that stable optical properties are achieved throughout the year, the cost of the device is reduced, and with required uniformity being met, the layer system can also be used to manufacture a large-scaled solar panel at low cost.