The reduction of carbon dioxide (CO₂) to syngas (a mixture of CO and H₂) can not only realize the carbon cycle and decrease the greenhouse effect but also alleviate the energy crisis. Design of catalyst is the key to realize CO₂ resource utilization. Herein, CuO and CuO/ZnO composite were prepared by metal ion co-precipitation method, and their performance of electrochemical CO₂ reduction to syngas under different potentials was investigated by adjusting the catalyst components. The results show that the introduction of zinc (Zn) species can decrease the adsorption intensity of intermediate CO₂^•- on the catalyst, which leads to the decrease of Faraday efficiency (FE) of CO and the increase of FE of H₂, thus achieving controllable regulation of CO/H₂ in the range of 1/1-1/4 under different applied electrochemical potential. In particular, the total FE of syngas CO/H₂ is up to 84% when the ratio of Cu to Zn in the precursor solution is 1 : 2.