The utility model provides a device is alleviated to high -speed railway tunnel micro -pressure wave, its structure is: at the fixed a plurality of T type baffles (2) in tunnel (1) inner wall interval, the surface of the web of baffle (2) is parallel with tunnel cross section (4), the pterygoid lamina of baffle (2) be convex and the radian similar with tunnel (1) inner wall radian, the pterygoid lamina axial of baffle (2) is parallel with tunnel axis (5). The utility model discloses can show and alleviate gradient before tunnel (1) internal pressure wave -wave, and then reach the purpose of alleviating tunnel (1) entrance to a cave micro -pressure wave, this micro -pressure wave is alleviated the mode and is set up than in tunnel (1) that the section enlarges section and service gallery has better cost advantage, in addition, to operation tunnel (1), the utility model discloses also a convenience, swift, economic and effectual device.