Abstract: Faced with the constraints of the “dual carbon” target, hydrogen energy, particularly the electrolysis of water for hydrogen production technology, has received significant attention. However, high energy consumption is one of the main problems hindering the industrialization of this technology. Based on this, a strategy to “Sacrificial anode carbon-assisted electrolysis of water for hydrogen production” is proposed, which utilizes the carbon oxidation reaction (COR) instead of the oxygen evolution reaction (OER) to achieve a significant reduction in energy consumption. Specifically, F-doped biochar (denoted as F-BC-850) was prepared using a simple two-step carbonization method, and its structural properties were analyzed using XRD, SEM-EDS, thermogravimetric analysis, XPS and other characterization methods. The structure-activity relationship between F-BC-850 and hydrogen production performance was elucidated by electrochemical methods. The results showed that the energy consumption of 0.5 mol/L H₂SO₄ solution at 10 mA/cm² was 57.9% of the energy consumption of a conventional Pt sheet electrode; Characterization results showed that HF generated by the pyrolysis of ammonium fluoride etched the biochar and formed highly active C−F bonds, which improved the oxidation performance of carbon. The addition of F species changed the carbon structure, promoted the decomposition of H₂O molecules to form *OH radicals, and enhanced the adsorption ability of carbon atoms for *OH radicals. This work can provide theoretical guidelines and scientific foundations for the efficient production of H₂ and high-quality utilization of biomass in carbon-assisted electrolysis of water for hydrogen production.