Surface engineering can adjust the electronic properties of catalysts, thereby boosting their electrocatalytic performances. Herein, S-doped and O-vacant mesoporous ZnO nanosheets (ZnO-VO-S) were synthesized through the plasma-treatment method, exhibiting highly electrocatalytic selectivity and activity in the conversion of CO2to CO. Synchrotron X-ray absorption fine structure (XAFS) investigations were used to further clarify the valence state and local coordination structure of Zn, concretely affirming the reduced electron density of Zn in ZnO-VO-S. Specifically, at −1.1 V vs. RHE, the as-prepared ZnO-VO-S demonstrated a high Faradaic efficiency of 90%. Experiments and density functional theory (DFT) suggest that the electron deficiency of Zn caused by the introduction of S dopant and O vacancy, reduces the energy barrier of CO2to CO by improving the adsorption behavior of the intermediate *COOH.