<p>Wood vinegar, as the primary byproduct of biomass pyrolysis, exhibits characteristics such as high COD concentration, complex organic composition, and environmental toxicity, necessitating the urgent development of efficient treatment technologies. This study established a zero-valent iron Fenton (ZVI-Fenton) pretreatment—anaerobic digestion (AD) coupled system. It not only investigated the effects of key pretreatment parameters on the degradation of COD and total phenols in wood vinegar but also clarified the effects of pretreatment conditions and sludge inoculum dosage on anaerobic digestion performance. Finally, high-throughput sequencing analysis was employed to characterize microbial communities. Results indicate that the concentrations of H₂O₂ and ZVI were 36&#xa0;mL/L and 24&#xa0;g/L, respectively, which represent the optimal pretreatment conditions. The optimal anaerobic digestion conditions were achieved with a sludge inoculum dosage of 15&#xa0;g, yielding a cumulative methane production of 314.5&#xa0;mL/g COD and a COD removal rate of 94.6%. This study confirms that the zero-valent iron Fenton coupled with anaerobic digestion technology can achieve efficient degradation of wood vinegar and energy recovery.</p> Graphical abstract <p></p>