Abstract: Taking a certain type of maglev rail vehicle as an example, to determine the load-bearing capacity of its vehicle structure under applied loads, and ensure its safety and reliability during use. So, it is necessary to conduct welding fatigue research on the main welds of the vehicle body. Set fatigue load conditions according to actual operating conditions and the provisions of EN 12663 standard. Calculate and extract result data through finite element simulation, using DVS 1608 standard for fatigue assessment of multiaxial stress. The calculation and analysis results indicate that, the stress utilization rate and comprehensive utilization rate in all directions obtained under all operating conditions are less than 1. The high utilization area is mainly concentrated at the connection between the end 2 underframe profile and the underframe edge beam. The fatigue strength of the vehicle body weld meets the design requirements