La0.6Sr0.4Fe0.8Mn0.2O3-δ(LSFM) perovskite cathode has an advantage in product control for solid oxide electrolysis cell, while it limited by its insufficient electrolysis current density. To improve its electrochemical performance, we developed a highly efficient composite cathode by mixing LSFM with CuFe2O4 spinel. In this study, CO2/H2O co-electrolysis were investigated using CuFe2O4, LSFM and their composites as cathodes on LaGaO3- based electrolyte. It was found that mixing LSFM and CuFe2O4 was effective for a significant increase in the electrolysis current density in co-electrolysis. Compared to the individual LSFM (0.60 A/cm2) and CuFe2O4 (1.00 A/cm2) cathode, a promising electrolysis current density of 1.43 A/cm2 was achieved at 1.6 V and 800oC with excellent Coulombic efficiency (> 95% of theoretical value), remarkable operation stability and reversibility in co-electrolysis. In addition, a homogeneous and uniform surface morphology with a well-distributed porous structure was observed on the LSFM-CuFe2O4 composite layer after the operation.