Solar-absorbing multilayers with beta-FeSi2-containing SiO2 composites were deposited on low-emissivity Mo base layers, and the optical reflectance spectra were obtained to investigate the solar-thermal conversion efficiency. Interband absorption of the beta-FeSi2 provided a desirable selective absorbing behaviour with a steep transition curve from high solar absorption to low infrared absorption in the near-infrared region. The beta-FeSi2 nanoparticles dispersed in the SiO2 matrices were stable even after annealing at 750 degrees C, and the optical constant spectra of the composite films were controllable by adjusting the beta-FeSi2 content. Although the interface between the beta-FeSi2 and Mo base layer had low thermal stability because of the diffusion of Si, a thin SiO2 barrier at the interlayer was effective in suppressing the interaction. The above findings were integrated into the designed multilayer "SiO2/beta-FeSi2+SiO2 composites/SiO2 barrier/Mo base", for which the optical absorption spectrum achieved high conversion efficiencies of over 72.3% at high temperatures below 700 degrees C.