With the advantages of computational efficiency and analytical flexibility, the Fourier transform method is widely used in the dynamic analysis of various engineering structures. In this chapter, the Fourier transform method is applied to the dynamic analysis of track structures under moving loads. By establishing single-layer, double-layer, and three-layer continuous elastic beam models for the track structure and deriving the vibration equations in the frequency domain, the algorithm for solving the dynamic response of the track structure using the Fourier transform method is presented. Based on the proposed model and algorithm, the source code, “Slab Track Dynamics Calculation Program STDYN_1.0,” developed using MATLAB mathematical tools, is provided in Appendix B. As application examples, two case studies are presented: the dynamic analysis of high-speed railway slab track structures and mixed passenger-freight railway track structures.