Back-to-Back Mechanically Stabilized Earth Walls (BBMSE) are used in the approach embankments for railway bridges under high-speed trains. The BBMSE walls have been adopted as a standard construction practice in Japan and are effectively used in the Mumbai to Ahmedabad high-speed rail (MAHSR) project. Though this technique is widely accepted, limited studies are available on the behavior of BBMSE walls under dynamic train loading in Indian conditions. Hence, this study aims to model and analyze the lateral earth pressures and lateral displacements at the wall facing along with the tension mobilized in the reinforcement at different levels. A numerical model of a BBMSE wall with a full height rigid (FHR) facing was developed in ABAQUS, a finite element modeling (FEM) package, to study the behavior of BBMSE walls under the dynamic train loading as per the MAHSR project. Furthermore, a two-dimensional model of a 6 m high BBMSE wall with reinforcements at 0.6 m vertical spacing is developed using a mesh size of 0.1 m (determined after the mesh sensitivity study). Thereafter, the model is subjected to dynamic train loading for a given wheel load of the train, loading frequency, and the duration of load application. For a given width-to-height ratio of the BBMSE wall (equal to 1.4), the model is analyzed for reinforcement stiffness varying from 500 kN/m (relatively flexible reinforcements) to 50,000 kN/m (relatively stiff reinforcement). FEM analyses showed that for the BBMSE wall with stiffer reinforcements, the lateral earth pressures and lateral displacements at the wall are reduced significantly.