The design and synthesis of solar steam generation materials is a green and promising approach to produce freshwater from seawater or contaminated water. Here, we develop a highly efficient and stable bilayer evaporator by assembling WO3-x nanorods (WO3-x NRs) onto a wood surface. Due to the broad-band absorption of the WO3-x NRs and the multiscatter of the incident light caused by the wood, the prepared solar evaporator with unique light trapping structures shows a high solar absorption (~94.0%). Additionally, combining with the merits of rapid water transport and heat localization, the energy conversion efficiency of the evaporator reaches as high as 82.5% under one sun irradiation and shows a stable water generation capability during long-term illumination cycles, which is one of the best performance compared with other wood-based materials and oxygen-defected tungsten oxide. The evaporator also shows great performance towards the evaporation of seawater and contaminated water, indicating great potential application. This work can provide reference for designing other high photothermal conversion system.