The speed increase of existing high-speed railway is limited, and the development trend of constructing low vacuum pipeline to run ultra-high-speed train is increasingly apparent. Using a three-dimensional, unsteady, compressible turbulence algorithm and slip grid technology, a coupling model of low vacuum pipeline and ultra-high-speed train is established to analyze the impact of train speed, vacuum pipeline vacuum, blockage ratio, and ambient temperature on the body surface pressure. Studies show that the measuring point pressure is basically unchanged along the length of the vehicle body, and is also basically unchanged at the same cross-section with the same train speed, the same low vacuum pipeline vacuum, cross-sectional area and temperature. The surface pressure amplitude of the head car, middle car and tail car is proportional to the 2.2 power of train speed, has a linear increasing relationship with blockage ratio, and has a linear increasing relationship with the environmental pressure of tube, which is basically not affected by temperature; The higher train speed, the higher the blockage ratio, and the higher environmental pressure of tube, the greater the amplitude of the pressure fluctuations on the surface of the car body when the train is running. © 2022, Science Press. All right reserved.