This paper reported an approach to the synthesis of prism-anchored octahedronal CeO2 nanostructure using hydro-thermal method. The morphology, structure, photoelectrochemical property of prism-anchored octahedronal CeO2 nanocomposite were investigated. The photoelectrochemical experiment revealed that growth of the prism arm on octahedron allowed to activate inert CeO2 octahedron for an increase in electrons transfer rates from bulk materials to solution under visible light. Furthermore, prism-anchored octahedronal CeO2 was utilized to achieve degradation of methyl orange and methylene blue effectively. The reusability, stability, and other results suggests that the prism-anchored octahedronal CeO2 nanostructure could be exploited as potential candidates for visible light photocatalysis, photovoltaic, and photoelectrochemical device.