Abstract: Under the global “dual carbon” strategy, coupling water electrolysis with biomass electrochemical conversion driven by renewable electricity enables the co-production of green hydrogen and high-value chemicals. This approach facilitates efficient storage of intermittent renewable energy in chemical form while improving the economic sustainability of biomass utilization, offering significant strategic importance. This review systematically summarizes recent advances in biomass electrochemical conversion coupled with water electrolysis for energy-saving hydrogen production. By replacing the oxygen evolution reaction with the oxidation of raw biomass and its derivatives, such as alcohols, furans, lignin, and biochar, this approach enables the low-energy hydrogen production alongside co-producing high-value chemicals like formic acid, 2,5-furandicarboxylic acid, and functional carbon materials, achieving synergistic optimization of energy conversion and resource cycling. Leveraging thermodynamic and kinetic advantages, advances in catalyst design and novel electrolyzer architectures have enabled stable operation at industrial current densities on the kilowatt scale, demonstrating engineering feasibility. Nevertheless, challenges remain, including selectivity control due to feedstock heterogeneity, rapid anode catalyst deactivation, and the high cost of large-scale mass transfer and product separation. Future breakthroughs should focus on designing highly active, selective, and durable electrocatalysts, innovating electrolyzer configurations and process systems, advancing mechanistic understanding through in-situ dynamic studies, and promoting integrated system design. These efforts will accelerate the transition from laboratory research to large-scale application, providing systematic solutions for the integrated development of green hydrogen energy and biomass refining.