To further enhance the catalytic activity of the perovskite-type oxide La_0.7Sr_0.3Cr_0.5Fe_0.5O_3-δ(LSCrF), non-stoichiometric defects were introduced at the A-site of the LSCrF material to prepare A-site deficient La_0.6Sr_0.3Cr_0.5Fe_0.5O_3-δ(A-LSCrF). The physical-chemical properties and electrochemical performance of the materials were investigated using a comprehensive set of characterization techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) analysis, thermogravimetric analysis (TGA), and electrochemical testing. The results indicate that the A-LSCrF sample exhibits uniform particle sizes, with a specific surface area and mean pore diameter of 1.70 m²·g^-1 and 14.08 nm, respectively. Under operating conditions, it generates a higher concentration of oxygen vacancies, which is beneficial in boosting catalytic activity. At 2.00 V, the current density of the LSCrF-based single cell is 0.73 A·cm^-1, whereas the A-LSCrF-based single cell achieves a current density of 1.38 A·cm^-1. These findings suggest that the introduction of A-site defects effectively increases the concentration of oxygen vacancies, thereby enhancing the cell's performance in electrochemical CO₂ reduction.