Abstract: Direct and selective conversion of methane to methanol under mild conditions still faces grand challenges. In this study, Co₃O₄/WO₃ nanocomposite catalysts were synthesized by facile hydrothermal method, combining with surface impregnation process. The structural composition and micro morphology of Co₃O₄/WO₃ composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and UV-visible absorption spectrum. The catalytic performance of Co₃O₄/WO₃ on the conversion of methane to methanol was investigated under visible light illumination at room temperature. The results show that incorporating Co₃O₄ can remarkably improve the photocatalytic performance of methane conversion. The optimal catalyst 3.0% Co₃O₄/WO₃ exhibits a methane conversion of 2041 μmol/g after visible light irradiation for 2 h, and the according methanol productivity and selectivity reach 1194 μmol/g and 58.5%, which are 4.03 and 2.39 times of single WO₃ respectively. This performance is superior to most reported heterogeneous photocatalysts for methane conversion, meanwhile possessing excellent cyclic stability. Combining the results of transient photocurrent and electron paramagnetic resonance (EPR) with the catalytic activity, the intrinsic mechanism of enhanced methane conversion via introducing Co₃O₄ is revealed, which is of theoretical significance to design light-driven catalysts for methane conversion to methanol.