Abstract: Reducing CO₂ into energy fuel is an effective way to alleviate the energy crisis and greenhouse effect. In recent years, domestic and foreign scholar have carried out extensive research on the photo(electro)catalytic reduction of CO₂. However, the photo(electro)catalytic reduction of CO₂ still has some problems, such as low visible light response, high recombination rate of photo-generated electrons and holes, small CO₂ adsorption and poor selectivity of products, which restrict the rapid development of this field. As a new type of green solvent, ionic liquids (ILs) have high thermal stability and strong CO₂ adsorption. They can be used as reaction medium or co-catalyst in the photo(electro)catalytic reduction of CO₂ chemical reactions, so they have been widely studied. In this paper, the research status and roles of ionic liquids in photo(electro)catalytic reduction of CO₂ in recent years are analyzed and reviewed, and the development prospect of ILs in this field is prospected.