Using visible light to convert CO₂ into CO and CH₄ is expected to solve the greenhouse effect and energy crisis at the same time. Z-scheme photocatalytic system has attracted widespread attention because it can minimize the recombination of photo generated electron-hole pairs and improve photocatalytic efficiency. In this work, g-C₃N₄/WO₃·H₂O (CNW-1) composite material was synthesized using hydrothermal method. The structure of catalysts was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, electron microscopy, etc.. The visible photocatalytic CO₂ reduction performance of CNW-1 under 298 K and 0.1 MPa conditions was investigated, and a possible reaction mechanism was proposed. The different yield of CO and CH₄ can be obtained by adjusting the content of water of crystallization in tungsten trioxide. After 10 h of reaction, CNW-1 has the highest yield of CH₄ (0.33 μmolg_-1^{), while} g-C₃N₄/WO₃ (CNW) has the highest CO yield (0.67 μmolg_-1⁾. This study not only provides an effective strategy for the selective reduction of CO₂ to C1 compounds, but also highlights the potential application of g-C₃N₄ by construct Z-scheme photocatalytic systems for field of catalysis.