An efficient photocatalyst of nitrogen (N)-doped Cu2O@CuO was constructed for H2O2 production under visible light simply by the one-step N2 plasma treatment for Cu2O octahedrons. It was discovered that the plasma treatment could allow for the simultaneous N doping and Cu2O oxidation to yield the N-doped Cu2O@CuO heterostructure so as to boost the separation and transferring of photogenerated carriers of photocatalysis. More interestingly, the photocatalytic performances of the N-doped Cu2O@CuO could controllably depend on the plasma treatment time, with the highest H2O2 production rate (about 14 μMg−1min−1) at the 10-min plasma treatment, which is over three and eight folds higher than that of Cu2O and CuO, respectively. Also, high photochemical stability of the photocatalyst could be expected for photocatalytic cycles. A two-step single electron transfer pathway was demonstrated for the photocatalytic oxygen reduction reactions of H2O2 evolution through the formation of dominated O2− radicals. This one-step plasma treatment route may provide a facile and efficient construction of photocatalytic heterostructures, promising for the large-scale applications for designing various efficient photocatalysts for H2O2 productions under visible light.