Higher demand on security of passenger railway nowadays leads to a trend of field testing method tried on the existing lines. Features of rail fastener are important parameters relevant to safety of railway track structure. Numerical model calculated to predict lateral features of rail fastening system investigates the relation between applied load and displacement of rail in order to provide a new idea of experiment design. The displacement of rail caused by torsional deformation is also considered. Nonlinear relationship of displacement response and load excitation discovered from experimental validation of a numerical model mainly lies in rail bending due to the dynamic response hardening (DRH). Consequently, clamping force which is only measured in the laboratory can be evaluated by both numerical and experimental analysis in this paper. Displacement distribution in longitudinal direction is also mentioned.