The impacts of oily wastewater on water quality, aquatic ecosystems and human health are a global problem. Therefore, the development of multifunctional oil-water separation materials, that are capable of organic pollutant removal, is of high importance and remains a significant challenge. Herein, we report a combination of 3D printing technology with hydrothermal method and liquid phase deposition to prepare a hierarchical TiO2/Cu2O porous lattice structure with 3D structure strengthening with oil-water separation performance and visible light catalytic degradation. Due to its micro-nano hierarchical structure, the as-prepared ceramic lattice structure exhibited very high levels of hydrophilicity and oleophobicity in aquatic environments. The 3D printed lattice structure achieved excellent oil-water separation performance, with the separation efficiency of the body-centered cubic lattice structure reaching 99.6%. Furthermore, organic pollutants dissolved in water can be decomposed by visible light irradiation after separation, improving the utilization rate of solar energy. The 3D printed lattice structure exhibited a compressive strength of 44.89 MPa and an absorption energy of 55.17 kJ m−3, indicating good mechanical strength and resistance to deformation. Overall, the use of 3D printing for structural strengthening of this multifunctional superhydrophilic and underwater superoleophobic lattice structure, is a promising method with a wide range of potential applications in environmental protection, particularly for the treatment of oily wastewater and the degradation of organic pollutants.