Harvesting energy from the water − solid interface through natural water evaporation provides a promising approach for generating sustainable electricity to power self-powered electronics. Advancing the bio-based hydrovoltaic materials enhances sustainability, with wood as a viable candidate due to the inherent hydrophilic and charged properties. However, current wood-based water evaporation-induced electricity generators (WEIGs) mainly depend on the “top-down” construction strategies. Wherein, the improvement of power density is constrained by the limited structural regulation, nondiverse building blocks, and monolithic enhancement mechanisms. Here, the high-performance wood-based WEIGs based on multiscale fibers network (MFN) are reported by embedding the Ti4O7 nanofibers (T4NF) inside the assemblies of TEMPO-oxidized cellulose nanofibrils (TOCNF) through a “bottom-up” route. Benefiting from the large specific surface area, high surface potential, and photothermal effect of conductive T4NF, the WEIG achieves a high short-circuit current of ∼13.7 μA while delivering ∼0.94 V open-circuit voltage. This work presents an efficient method to boost performance while understanding the impact of functional MFN on water evaporation.