The double perovskite oxides are widely investigated as cathode materials for solid oxide fuel cell (SOFC) due to their superior ionic electron conductivity. In this work, Pr0.9Ca0.1Ba1-xCaxCo2O5+δ (0≤x≤0.3, PCBC) was prepared by a modified complexing sol-gel process. Based on the electrical conductivity results, Ca ion co-doping can effectively improve the conductivity of the material. The electrochemical performance results indicate that the cathode with x of 0.2 has the optimum oxygen catalytic activity, and the polarization impedance is only 0.069 ?偸cm2 at 700 ℃. The oxygen vacancy formation energy, density of states, as well as O s and O p band center of PrBaCo2O5+δ, Pr0.75Ca0.25BaCo2O5+δ, and Pr0.75Ca0.25Ba0.75Ca0.25Co2O5+δ materials were calculated based on the GGA-PBE function. It is indicated that Pr-site doped with Ca can reduce the oxygen vacancy formation energy, while Ba-site doped with Ca can increase the oxygen vacancy formation energy. The calculation results of O p band center show that the strategy of Ba-site doped with Ca can effectively increase the oxygen reduction activity. The co-doping strategy of double perovskite can improve the thermal expansion, conductivity, electrochemical performance, and long-term stability of the material.