The invention provides a cushion layer under a rail and a vibration attenuation rail, and belongs to rail traffic vibration attenuation equipment. The cushion layer under the rail is used for being installed between a ballast bed and a steel rail and composed of one or more wave resistance layers, each wave resistance layer includes a plurality of wave resistance units fixedly connected with one another, each wave resistance unit comprises a substrate which is internally provided with a containing space and a scatter, and coating layers used for fixing the scatters are arranged between the substrates and the scatters; the cushion layer under the rail includes a first surface close to or away from the steel rail, a second surface opposite to the first surface and a third surface perpendicular to the first surface; each substrate includes an opening, and the openings of all the wave resistance units of the cushion layer under the rail all face the third surface. The cushion layer under the rail can effectively reduce vibration of rail traffic, and the vibration attenuation rail applying the cushion layer under the rail can reduce vibration transmission of the rail structure.