Rational design hybrid nanostructure photocatalysts with efficient charge separation and transfer, and good solar light harvesting ability have critical significance for achieving high solar-to-chemical conversion efficiency. Here a highly active and stable composite photocatalyst is reported by integrating ultrathin ZnIn S nanosheets on surface of hollow CdS cube to form the cube-in-cube structure. Experimental results combined with density functional theory calculations confirm that the Z-scheme ZnIn S /CdS heterojunction is formed, which highly boosts the charge separation and transfer under the local-electric-field at semiconductor/semiconductor interface, and thus prolongs their lifetimes. Moreover, such a structure affords the highly enhanced light-harvesting property. The optimized ZnIn S /CdS nanohybrids exhibit superior H generation rate under visible-light irradiation (λ ≥ 420 nm) with excellent photochemical stability during 20 h continuous operation.