Fabricating catalysts with efficient water dissociation and robust stability is key to advancing the industrialization of the alkaline hydrogen evolution reaction (HER). Establishing an effective phosphide/oxide interface is a feasible way to improve the HER performance of the catalyst in an alkaline medium, but it remains challenging. Here, we adopt that manganese oxide nanoparticles decorated on nickel-cobalt phosphide nanowire array on nickel foam (MnO_x@NiCoP/NF) via a surface modification strategy that shifts the d-band center downward, promoting the water dissociation and hydrogen intermediate binding. Moreover, MnO_x makes the surface of NiCoP rougher, facilitating bubble release and improving the array stability. Consequently, MnO_x@NiCoP/NF achieves industrial current densities of 500 and 1000 mA cm⁻² with overpotentials of 171 and 193 mV, respectively, while maintaining stable operation for over 600 h at 1000 mA cm⁻² in 1 M KOH. Additionally, an anion exchange membrane electrolyzer with the catalyst was fabricated and shows potential for practical applications.