The electrocatalytic reduction of carbon dioxide (CO₂) into fuels or chemicals using renewable energy sources is an ideal means of achieving an artificial carbon cycle. However, the activity, selectivity and stability of catalysts limit the application of electrocatalytic CO₂ reduction reactions. Single-atom metal catalysts on the carbon-based materials (M-SACs@C) have attracted extensive attention of researchers due to their high activity, high selectivity and high metal atom utilization, which are ideal catalysts for electrocatalytic CO₂ reduction. M-SACs@C can convert CO₂ into carbon monoxide, formic acid, methane, methanol, ethanol, etc. This review provides an overview of the application of M-SACs@C in CO₂ reduction reactions from the perspective of CO₂ reduction product species. We focused on the single-atom site configuration and the source of activity. In addition, the mechanisms of M-SACs@C in CO₂ reduction reactions are also analyzed and prospected in this review. The controlled synthesis of homogeneous and highly loaded M-SACs@C, clarification of the mechanism of CO₂ reduction reaction and enhancement of the stability of the active site are the necessary paths for the industrialization of M-SACs@C.