A key challenge for the conversion of 5-hydroxymethylfurfural (HMF) into value-added 2,5-furandicarboxylic acid (FDCA) is improving the sluggish kinetics of selective oxidation alcohol groups. Electrocatalysis has been proved to be a green and efficient strategy for heterogeneous synthetic chemistry. Herein, we report an electrocatalyst of [email protected]x core-shell nanowires for efficiently upgrading HMF into FDCA. The [email protected]x features conductive NiSe nanowires as a core and active NiOx as a shell, showing a smaller Tafel slope of 23 mV dec−1 accompanying with a near-quantitative yield of FDCA and 99% Faradaic efficiency (FE). X-ray photoelectron spectroscopy unveils the high valence of Ni species in the NiOx shell may be the active sites. Further integrated electrolyzer can produce FDCA and hydrogen simultaneously, showing a 100% FE even after six successive cycles, disclosing robust stability. All these results demonstrate [email protected]x core-shell nanowires as a promising robust non-precious electrocatalyst for highly efficient biomass transformation.