A method for producing 2,5-furandicarboxylic acid (FDCA) by electrocatalytic oxidation of 5-hydroxymethylfurfural (HMF) is provided, where the catalytic oxidation is conducted using an electrolytic cell; the electrolytic cell is a three-electrode electrolytic cell or a two-electrode electrolytic cell; an anode used is a monolithic electrode; the monolithic electrode includes a carrier and a catalytically active substance loaded on the carrier; and the catalytically active substance includes cobaltosic oxide particle-encapsulated nitrogen-doped carbon nanowires. The method has high activity and high selectivity, and the anodic catalyst is highly tolerant to HMF.