According to the structure and technical features of high-speed railway， the high-speed train， rail line， air flow， power supply and catenary which are relevant to the high-speed train and have an effect on the dynamic behavior of the high-speed train are coupled as a unified system. The dynamic model of coupled systems in high-speed trains are created by establishing the dynamic models of high-speed train， rail line， pantograph-catenary and power supply and the coupled interaction models of wheel-rail， pantograph-catenary， liquid-solid and electro-mechanical. For the high speed train operation simulation requirements， this paper studied the train dynamics modeling and calculation method based on cyclic variable parameters method， the train-line coupled calculation method based on the slip model and the liquid-solid coupled calculation method based on the relaxation factor. the simulation of coupled systems in high-speed trains are realized. [Key words] high-speed train； service performance； train detection； tracking test； performance evolution