<p>Biomass valorization represents a critical frontier in green chemistry and energy chemistry, where the essence of transformation lies in the selective cleavage and reconstruction of key chemical bonds. Electrocatalysis, characterized by mild operating conditions and an environmentally benign nature, offers a highly promising and sustainable pathway for upgrading waste biomass into value-added products. From the perspective of chemical bonds, this review systematically summarizes the latest research progress in electrocatalytic biomass valorization. First, the underlying microscopic electron/proton transfer mechanisms involved in electrocatalytic oxidation and reduction are discussed. Next, the cleavage and reconstruction of key chemical bonds, including C–H, C–O, C–C, C–N, and C–S bonds, are highlighted, with an in-depth analysis of substrate activation mechanisms, reaction pathways, and corresponding catalyst design strategies. Additionally, this review analyzes the regulatory mechanisms by which the interfacial microenvironment governs the conversion selectivity of different chemical bonds. Finally, perspectives on the core challenges currently facing this field are provided, including the insufficient elucidation of dynamic reaction mechanisms, the limited development of industrial-grade and stable catalysts, and the slow progress in scaling up electrolysis devices and processes. This review aims to provide theoretical guidance and new insights for the rational design of highly selective electrocatalysts for biomass valorization.</p> Graphical Abstract <p>This review summarizes key advances in electrocatalytic biomass valorization from the perspective of chemical bonds, focusing on the selective cleavage and reconstruction of C–H, C–O, C–C, C–N, and C–S bonds, substrate activation pathways, and rational catalyst design, offering theoretical guidance for designing highly selective electrocatalysts for biomass upgrading.</p> <p></p>