Engineering 3D dual-functional electrodes with non-noble metals toward efficient overall water electrolysis is significantly important but challenging for the renewable chemical fuels. Here, vanadium doped Ni3S2 nanosheets array decorated on carbon fiber cloth (V-Ni3S2/CC) is successfully constructed as 3D dual-functional electrodes for efficient overall water splitting. The specific nanosheet array electrode provides structural benefits of high contact area, abundant accessible catalytic sites, shortened and accelerated charge transfer, and improved electrolyte penetration. Moreover, the vanadium dopants have a positive effect on the catalysis process, contributing to the improved intrinsic activity and accelerated catalysis reaction kinetics of Ni3S2 catalyst. Reasonably, the developed V-Ni3S2/CC electrodes exhibit robust water splitting performances, with small overpotential of 180 mV for oxygen evolution reaction and 81 mV for hydrogen evolution reaction at 10 mA cm(-2). In a V-Ni3S2/CC dual-electrodes constructed electrolyzer system, an ultralow cell potential of 1.49 V is achieved for a stable catalytic current of 10 mA cm(-2), outperforming most of the reported non-noble metals based dual-functional electrocatalysts.