Abstract: The micro-pressure wave at the tunnel exit caused by a high-speed maglev train at 600 km/h can affect the environment. Based on the finite volume method, overset mesh technique, and the SST k-ω turbulence model, a numerical simulation was conducted to investigate the three-dimensional compressible unsteady turbulent flow during a five-car formation high-speed maglev train running through a tunnel at 600 km/h. The effect of the buffer hood with an oblique brim at the entry and exit portals on the micro-pressure wave was analyzed under the most unfavorable tunnel length. The hood splits the initial compression wave into two pressure-rise stages. With a constant cross-section, increasing the hood length first reduces and then raises the first-stage pressure gradient, while the second-stage gradient changes little. With a constant length, a larger cross-section lowers the first-stage gradient but raises the second-stage gradient. With a hood area 2.5 times the tunnel area and a length of 60 m, the reduction of the micro-pressure wave amplitude reaches its maximum at points 20 m and 50 m outside the tunnel exit, with reduction rates of 72.39% and 66.82%, respectively. The optimal length is 60 m for a hood-to-tunnel cross-sectional area ratio of 1.5, 80 m for a ratio of 2.0, and 60 m for ratios of 2.5 and 3.0, respectively. As the hood section area continues to increase, the optimal length stabilizes at 60 m. These findings can provide useful reference for the design of buffer hoods aimed at weakening the micro-pressure waves induced by high-speed maglev trains passing through tunnels.