Exploring cost-effective, sustainable, and corrosion-resistant freestanding electrodes for the hydrogen evolution reaction (HER) coupled with biomass upgrading is essential for improving energy efficiency, but remains a challenge. Herein, we report a hierarchical wood-derived carbon electrode fabricated by encapsulating CoP₃/CoMoO₄ heterostructures within carbonized wood (CoP₃/CoMoO₄@CW). This bifunctional electrocatalyst exhibits remarkable performance, achieving ultralow HER overpotentials of 33 and 158 mV at current densities of 10 and 100 mA·cm⁻², respectively, surpassing most wood-based works, while maintaining a high Faradaic efficiency of 93% for xylose-to-formate conversion. Experimental results and density functional theory calculations reveal that the exceptional catalytic performance originates from the hierarchical porous architecture that enables efficient mass transport, abundant heterointerfaces that promote xylose adsorption/activation, and an optimized electronic structure that lowers the water dissociation energy barrier while facilitating H^* intermediate adsorption–desorption thermodynamics. This approach offers a viable strategy for high-performance electrocatalysts for efficient hydrogen production and biomass valorization.