Abstract: The conversion of CO₂ into carbon-based fuels through artificial photosynthesis technology based on semiconductor photocatalytic reduction has been identified as an ideal strategy to alleviate energy shortage and environmental crisis. However, due to insufficient utilization of solar energy and rapid recombination of photogenerated charges for the reported photocatalysts, the energy conversion efficiency of CO₂ photoreduction is still low. Amorphous CoO_x/WO_3-x composite photocatalysts were synthesized by a hydrothermal method combining with surface impregnation process for the first time. Crystal phase composition, microstructure, optical absorption properties and oxygen vacancy defects of the prepared catalysts were systematically characterized by XRD, TEM, XPS, EPR and UV-Vis-NIR DRS. The results of CO₂ photoreduction experiments show that only 3.2 μmol·g⁻¹ CH₄ can be detected when using WO_3-x as a catalyst after Vis-NIR light irradiation for 3 h, whereas introducing CoO_x can significantly boost the CO₂ photocatalytic reduction performance of WO_3-x. Under the same experimental conditions, the yield of CO and CH₄ on 2.5wt%CoO_x/WO_3-x catalyst can reach 78.2 and 19.7 μmol·g⁻¹ respectively. Introducing oxygen vacancies can form a new intermediate energy level in the band structure of WO_3-x, which enhances NIR absorption and causes local temperature rise of the catalysts surface. Incorporating CoO_x contributes to enhance the separation and migration of photogenerated charges, and meanwhile can regulate the conduction-band potential of WO_3-x. The synergistic effect of photothermal effect and CoO_x cocatalyst is the primary reason for the promoted performance of CO₂ photocatalytic conversion. Additionally, the composite photocatalysts CoO_x/WO_3-x shows excellent long-term catalytic and structural stability.