In this paper, W₁₈O₄₉ nano-/micro-structures (NMS) were first prepared by evaporating of WO₃ and elemental S powders, and then W₁₈O₄₉@Cu₂O NMS composite was successfully fabricated by dipping the prepared W₁₈O₄₉NMS in saturated cupric acetate solution and thereafter thermal treatment. The prepared W₁₈O₄₉NMS and the finally obtained W₁₈O₄₉@Cu₂O NMS composite were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy and transmission electron microscopy. Finally, the photocatalytic performances of the prepared W₁₈O₄₉NMS and the final W₁₈O₄₉@Cu₂O NMS composite were evaluated by the degradation of methylene blue under simulated sunlight irradiation. It was revealed that a longer dipping time would result in more Cu₂O loaded on the W₁₈O₄₉ NMS; and the loading of Cu₂O on W₁₈O₄₉ NMS can effectively improve its photocatalytic performance.