Rational design of highly efficient electrocatalysts for sustainable energy conversion is critical but also challenging. Both the composition and surface property of catalyst are pivotal for the advanced water electrolysis. Herein, the Ru/Co(OH) nanosheet array with tunable compactness on carbon cloth is designed via a facile two-step process. Especially, the as-synthesized Ru/Co(OH) nanosheet array with superhydrophilicity and superaerophobicity surface is conducive to the acceleration of mass transport, which is realized by facilitating the access of electrolyte and alleviating the “bubble shielding effect” for gas bubble diffusion. Consequently, the fabricated nanostructured Ru/Co(OH) array based catalyst shows an outstanding HER performance in 1.0 M KOH, which only requires a low overpotential of 35 mV to reach 10 mA cm and demonstrates strong stability at a high current density of 500 mA cm upon long-term duration operation. Additionally, the enhanced Faradic efficiency under high current density is achieved by the optimized nanoarray structure. It is believed the present work could provide a novel perspective for tuning the catalytic activities of nanostructured electrode and beyond.