China is a country with a large distribution of frozen soil. Railway tracks in cold regions are generally affected by frost heaving of foundation soil. Previous studies focused on the frost heave characteristics of foundation soil, but paid less attention to the interaction between railway and foundation soil under longitudinal non-uniform frost heave deformation. Based on the beam theory of double-layer elastic foundation, this paper establishes the mechanical model of rail under rail foundation under the action of non-uniform frost heaving deformation, gives the analytical solution of the model, and analyzes the effects of interlayer elastic coefficient and frost heaving on track displacement and internal force combined with an example. The results show that the elastic interlayer can effectively reduce the frost heave deformation and stress response of the rail, which is conducive to the operation of the rail; The length of the transition section between the rail and the foundation under the rail, the shear force and bending moment at the concave convex bending section increase with the increase of frost heave displacement; The increase of the elastic coefficient of the interlayer will cause the influence of frost heaving force on the foundation under the track to gradually transfer to the track; The length of the transition section is only related to the amount of frost heaving. The calculation method and analysis conclusion proposed in this paper can provide scientific guidance for railway design, operation and maintenance in cold regions.