Electrocatalytic water splitting offers a sustainable route for hydrogen production, enabling the clean and renewable alternative energy system of hydrogen economy. The scarcity and high-cost of platinum-group-metal (PGM) materials urge the exploration of high-performance non-PGM electrocatalysts. Herein, a unique hierarchical structure of Ni/V₂O₃ with extraordinary electrocatalytic performance (e.g., overpotentials as low as 22 mV at 20 mA·cm^-2 and 94 mV at 100 mA·cm^-2) toward hydrogen evolution reaction in alkaline electrolyte (1 M KOH) is reported. The investigation on the hierarchical Ni/V₂O₃ with a bimodal size-distribution also offers insight of interfacial engineering that only proper Ni/V₂O₃ interface can effectively improve H₂O adsorption, H₂O dissociation as well as H adsorption, for an efficient hydrogen production.