The alignment of the track and its compatibility with the subgrade structures largely determine the dynamic response of the vehicle-track system and directly impact the operational quality. Conducting dynamic evaluation and optimization during the line scheme research phase is of great significance for improving the train's dynamic performance after the high-speed railway begins operation and reducing the maintenance and repair costs of the subgrade structures. Furthermore, in overseas high-speed railway projects, a dynamic performance evaluation report of the line scheme is often required. This chapter introduces the application of track system dynamics theory in the dynamic evaluation and optimization of high-speed railway line schemes, based on the dynamic model and the line scheme evaluation indicators and methods established earlier, using actual engineering cases such as the Beijing-Shenyang High-Speed Railway (Jinshen HSR) and the Jakarta-Bandung High-Speed Railway of Indonesia.