Abstract: Due to the presence of a large number of aromatic rings in lignin, which form a three-dimensional network of macromolecules through C_α—C_β and C_β—O—C linkages, lignin possesses enormous potential for the conversion of phenolic monomers and energy compounds. However, key challenges in the depolymerization of lignin—such as the difficulty in breaking C_α—C_β(75-118 kcal·mol⁻¹) and C_β—O—C(20-62 kcal·mol⁻¹) bonds—have long plagued researchers both domestically and internationally. To address these issues, this study employed a one-step hydrothermal method using Co and Mo bimetallic dopants to prepare Mo-TiO₂ and CoMo-TiO₂ composite catalysts. This approach resolves the problems of low depolymerization rates, diverse byproducts, and low product yields in the electrocatalytic depolymerization of lignin. The addition of the molybdenum component provides more active sites, significantly improving depolymerization efficiency, while the addition of the cobalt component increases product selectivity, thereby reducing the formation of byproducts. The results show that the Mo-TiO₂ composite catalyst achieves a depolymerization efficiency of up to 86.44% under optimal conditions, while the CoMo-TiO₂ composite catalyst reaches as high as 99.24% under optimal conditions, with a yield of the main product, benzaldehyde, as high as 102.58 mg·g⁻¹ and no other byproducts generated. Mechanistic studies from a radical perspective demonstrate that the composite catalyst adsorbs water molecules and the substrate PPE-OL in the electrolytic cell. Water molecules undergo electrolysis on its surface to generate hydroxyl radicals that attack the unstable C_α—C_β bond. The oxygen vacancies abundant in the composite catalyst provide more high-quality active sites for the electrooxidation reaction, generating high concentrations of ROS, which promote the oxidative cleavage of the substrate’s C_α—C_β bond and the oxidation of intermediates, exhibiting high selectivity toward benzaldehyde.