Converting carbon dioxide (CO2) to high-energy chemicals through electrocatalytic CO2 reduction reaction (CO2RR) is a powerful way to solve the greenhouse effect and realize the anthropogenic carbon cycle. Compared with other metal catalysts, copper (Cu)-based catalysts have attracted much attention due to the ability to generate multi-carbon products. However, it has poor selectivity for the products. Hence, efforts have been made in recent years to investigate the mechanism and influencing factors of C-C coupling in the reaction process of Cu-based catalysts, and to carry out targeted structural design and experimental synthesis of Cu-based catalysts. This paper first summarized the basic principles of electrocatalytic CO2RR. Then, the five key factors (electrocatalytic reactor, pH, pressure, temperature, CO2 flow rate and concentration) affecting electrocatalytic CO2RR were summarized. Next, related strategies (alloying, nanostructure modification, heteroatom doping, hydrophilic/hydrophobic and Single atom catalysts) for modification of Cu-based catalysts were reviewed. Finally, the current opportunities and challenges for the preparation of Cu-based catalysts for electrocatalytic CO2RR were prospected, in order to provide valuable insights and ideas for future research in related fields.