Time-resolved X-ray absorption fine structure spectrum technology needs to produce X-ray source with high brightness, uniform and wide spectrum. The M-band radiation source generated by an elementary target has high brightness, but poor uniformity. Therefore, this paper proposes a scheme to generate M-band radiation using a multilayer composite target prepared by a variety of metallic materials. For the K edge X-ray absorption spectroscopy experiment of Si, the optimal material ratio was theoretically calculated according to the previous elementary target M-band spectrum experiment data, and the multilayer composite target composed of Au, Yb, Dy was prepared. The radiation spectrum measurement of the multilayer composite target driven by pulse laser was carried out on the Shenguang II laser facility, and the experimental results were basically consistent with the theoretical calculation. Compared with an elementary target, the M-band radiation source generated by multilayer composite target has the advantages of wide spectrum and uniform overall brightness, and has great application potential in time-resolved X-ray absorption fine structure spectroscopy experiments.