The Sc-doped La0.6Sr0.4Co0.2Fe0.8-XScxO3-? (LSCFScx, x=0, 0.04, 0.08) cathode powders were synthesized by a sol-gel method. The crystal structure, chemical morphology of surface elements, catalytic activity and electrochemical properties of LSCFSc cathode material were systematically analyzed.XRD results show that LSCF has a cubic structure, and the LSCFSc cathode material changes from cubic to hexagonal structure.The conductivity of LSCFSc cathode material decreases with the Sc3+-doping, and the conductivity of LSCFSc0.08 cathode sample is still greater than 100 S/cm in the temperature range of 300-800.XPS results show that Sc3+-doping increases the content of adsorbed oxygen (OAds) on the surface of LSCFSc cathode material, and the RASR of polarization surface of LSCFSc0.08 cathode material measured at 800℃ is 0.026 Ω·cm2, which is about 87.6% lower than RASR of LSCF cathode material, which significantly improved the adsorption/dissociation ability of LSCFSc cathode material to oxygen, and enhanced the catalytic activity of oxygen.Ni-SDC as the anode material, SDC as electrolyte, and LSCFSc0.08 as cathode material assembled into Ni-SDC|SDC|LSCFSc0.08 anode-support single cell, the maximum power density is 806 mW/cm2 at 800 ℃, indicating that Sc3+-doping can significantly improved the electrochemical performance of cathode materials.