The continuous consumption of fossil energy and excessive emissions of carbon dioxide (CO2) have caused a serious energy crisis and led to the greenhouse effect. Using natural resources to convert CO2into fuel or high-value chemicals is considered to be an effective solution. Photoelectrochemical (PEC) catalysis utilizes abundant solar energy resources, combined with the advantages of photocatalysis (PC) and electrocatalysis (EC), to achieve efficient CO2conversion. In this review, the basic principles and evaluation criteria, of PEC catalytic reduction to CO2(PEC CO2RR), are introduced. Next, the recent research progress on typical kinds of photocathode materials for CO2reduction are reviewed, and the structure–function relationships between material composition/structure and activity/selectivity are discussed. Finally, the possible catalytic mechanisms and the challenges of using PEC to reduce CO2are proposed.