To analyze the unsteady three-dimensional flow in the subway tunnel caused by the passage of a train, both experimental and computational studies have been conducted. The experimental analysis of train-induced unsteady flow is conducted on a 1/20 scale model tunnel and the pressure and air velocity variations with time are presented. The three-dimensional unsteady numerical analysis using the sharp interface method for the moving boundary of an immersed solid was carried out for the same geometric configurations as the experimental analysis. The predicted numerical model results show good agreement with the experimental data.