To improve the photocatalytic activity and photostability of ZnO, a novel cable-like Pt/ZnO@C composite is successfully fabricated by coating a 3-5 nm hydrothermal carbon (HTC) layer on the surface of the Pt nanoparticle-modified ZnO nanowire. After investigating the optical and photoelectrochemical performance in detail, it is found that the Pt/ZnO@C nanocable shows a dual-enhanced migration efficiency for the photoinduced surface electrons, distributing to the modified Pt nanoparticles and the coated HTC layer. Consequently, the Pt/ZnO@C nanocable exhibits a dual-enhanced photocatalytic activity for the degradation of various organic pollutants under the UV light irradiation. The coated HTC layer can also play a role in suspending the ZnO photocorrosion and significantly improves the photostability of the Pt/ZnO@C nanocable. Furthermore, the photocatalysis and photocorrosion mechanism of the Pt/ZnO@C nanocable is proposed and discussed in terms of its structural feature and photoelectrochemical property. The resultant Pt/ZnO@C nanocable with the unique HTC layer-coated structure will probably stimulate to design and synthesize more HTC-hybridized composites with a superior photocatalytic or photoelectrocatalytic performance.