Synthesis of reduced graphene oxide/TiO₂ nanotubes (rGO/TNTs) composite is being attended. However, the synthesis of rGO/TNTs composite directly from graphite oxide with a greener approach is still challenging. In this study, we directly synthesized rGO/TNTs composite by a simple method from graphite oxide and titanium dioxide nanotube (TNTs) powder without involving any assistant agents. The formation of the graphene oxide (GO) was confirmed by X-ray diffraction (XRD) pattern, transmission electron microscope (TEM) image, Fourier-transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Besides, photoluminescence analysis (PL) was conducted to determine the defects of materials. The methylene blue (MB) photodegradation efficiency under visible light of rGO/TNTs composite achieved 80% after 180 min. In addition, the key of the photocatalytic mechanism of rGO/TNTs under visible light was systematically investigated via trapping experiments.