Converting CO2 into value‐added products by photocatalysis, electrocatalysis, and photoelectrocatalysis is a promising method to alleviate the global environmental problems and energy crisis. Among the semiconductor materials applied in CO2 catalytic reduction, Cu2O has the advantages of abundant reserves, low price and environmental friendliness. Moreover, Cu2O has unique adsorption and activation properties for CO2, which is conducive to the generation of C2+ products through CC coupling. This review introduces the basic principles of CO2 reduction and summarizes the pathways for the generation of C1, C2, and C2+ products. The factors affecting CO2 reduction performance are further discussed from the perspective of the reaction environment, medium, and novel reactor design. Then, the properties of Cu2O‐based catalysts in CO2 reduction are summarized and several optimization strategies to enhance their stability and redox capacity are discussed. Subsequently, the application of Cu2O‐based catalysts in photocatalytic, electrocatalytic, and photoelectrocatalytic CO2 reduction is described. Finally, the opportunities, challenges and several research directions of Cu2O‐based catalysts in the field of CO2 catalytic reduction are presented, which is guidance for its wide application in the energy and environmental fields is provided. This review focus on the research progress of Cu2O‐based catalysts applied in photo‐, electro‐, and photoelectrocatalytic reduction of CO2. The properties of Cu2O‐based catalysts in CO2 reduction and several optimization strategies to enhance its performance are also discussed.