Solar-energy-driven hydrogen production from biomass is a key technology for green hydrogen production. Photothermal synergistic catalysis is an effective means to enhance biological hydrogen production. In this study, a spectral beam splitter coating (SBSC) adapted for photothermal synergetic catalysis is designed and developed based on cesium tungsten bronze (CWO) and silicon dioxide (SiO2) in a sol–gel system. The CWO/SiO2 SBSC exhibits short-wavelength transmittance up to 85.7 % and absorption of near-infrared (NIR) light up to 91.3 % by adjusting the lifting speed, filling factor, and curing temperature. Evaluation model calculations reveal that the CWO/SiO2 SBSC can significantly improve the hydrogen production rate when the reaction solution temperature is 80 °C and that the integrated solar energy conversion efficiency is 3.7 times that without the SBSC. The results demonstrate the high durability of the CWO/SiO2 SBSC as well as its promising application scope in the photothermal synergetic catalysis of biomass hydrogen.