Abstract: The novel multi-beam X-ray source is expected to advance the development of tomographic imaging. As a key component, the multi-beam X-ray tube integrates numerous cathode-anode assemblies within its internal structure. Its innovative vacuum chamber and X-ray window structures require focused research. Targeting chest tomographic applications, this study conducted the structural design of a long cylindrical vacuum chamber and a linear array X-ray window for a multi-beam X-ray tube. Finite element simulation and analysis were conducted to evaluate the stress distribution and chamber deformation across different structural configurations. A segmented multi-window design was proposed, followed by design, fabrication and validation testing. An optimized design was achieved for a medical-grade multi-beam X-ray tube with 63 focal spots. The vacuum chamber has a wall thickness of 3 mm, with seven linearly arranged windows emitting X-rays. Each focal spot’s beam fully covers a 43 cm×43 cm detector positioned centrally ahead. The measured weight of the X-ray tube is 35.6 kg. The maximum inward deformation of each surface is 0.31 mm, and the maximum deformation width of the X-ray window is 0.092 mm. The maximum stress of the vacuum chamber, as calculated through finite element simulation, is 1.692×10⁸ N/m². All performance indicators meet the expected requirements. The finite element analysis effectively guided the structural optimization, enabling the vacuum chamber to achieve a lightweight design, minimal deformation and low stress levels. This work offers a valuable reference for the structure design of vacuum chambers in similar applications.