Abstract: Targeting the air delivery duct structure of a metro vehicle compartment, the STAR\|CCM+ software is used to analyze its air supply uniformity. The calculation results show that when adopting the initial air delivery duct structure, the air volume of both ends of the compartment is relatively larger, the mass flow deviation of each sectional air supply outlet from the overall average value is relatively higher, and the standard deviation of relative error is also relatively larger, so the uniformity of compartment air supply is relatively poor. By methods such as changing air delivery duct structure and adding main duct internal baffle, the initial air delivery duct structure is optimized, and the mass flow of each sectional air supply outlet after optimization becomes closer to the overall average value, and the standard deviation of relative error is reduced, with the uniformity of compartment air supply being significantly improved.