CdS-Pt@CeO ternary composites are successfully prepared by an in situ redox precipitation followed by a subsequent precipitation. The prepared CdS-Pt@CeO sample exhibits high photocatalytic activity for hydrogen evolution from lactic acid aqueous solution under visible light irradiation, with a H-evolation rate of 20.09 mmol hg and apparent quantum yield (AQY) of 15.32%. With techniques such as XRD, TEM, DRS, XPS, N adsorption/desorption and electrochemistry measurements, the physicochemical properties of the CdS-Pt@CeO ternary composites are discussed, and a possible mechanism for the hydrogen evolution is proposed.