The effectiveness of smoke discharge and air supply of evacuation gallery are the keys to personnel safety. Field test is carried out to verify the effectiveness of pressurized air supply system of evacuation gallery of a typical shield tunnel. The optimized scheme of arrangement of pressurized air supply vents is proposed; the false air volume is reduced by 25%; and the optimized scheme is simulated by CFD software. Two separation walls are set on bottom of roadway, so as to form closed slide room and independent evacuation gallery and further improve the safety of the system.