A novel Cu2O/Carbon Nanotubes (CNTs) hierarchical chrysanthemum-like nanocomposite has been successfully synthesized by a facile wet chemical method for the first time. This kind of nanostructure is made of three-dimensional (3D) ordered structures with an average diameter of about 80–120nm. A possible growth mechanism of the Cu2O/CNTs chrysanthemum-like nanocomposites was proposed. Moreover, the novel chrysanthemum-like structure enlarged the range of absorbed light and enhanced the absorption intensity of light. The as-obtained Cu2O/CNTs samples were evaluated for their ability in the degradation of phenol under visible light irradiation. Compared with other as-prepared Cu2O/CNTs products, the Cu2O/CNTs chrysanthemum-like nanocomposite exhibited superior property on photocatalytic decomposition of phenol. It is believed that the efficient potocatalytic properties are originated from their unique 3D ordered nanostructures, which is highly beneficial to the reagent diffusion and mass transportation.