Abstract: In order to slow down the pressure fluctuation caused by high-speed train passing through tunnel, the influence of the connected aisle on the pressure wave characteristics of high-speed train passing through tunnel is studied. A numerical simulation model for three-section formation high-speed train is established. Based on three-dimensional, unsteady, compressible Navier-Stokes equation and k-ε two-equation turbulence model and slip grid technology, the aerodynamic characteristics of high-speed train passing through tunnel with connected aisle are numerically simulated. Research results show that compared to tunnel without connected aisle, the aerodynamic characteristics of train passing through tunnel with connected aisle is evidently improved; tunnel with connected aisle shows more visible effect on the suppression of initial pressure rise and fall, and the suppression of the expansion wave is more prominent; setting connected aisle makes the pressure wave waveform partially jagged.