Abstract: The structure design of high voltage power supply of airborne traveling wave tube transmitter is discussed in detail from the aspects of composition, structure design, insulation design and thermal design of high voltage power supply. A plug-in type modular structure is put forward. The interior of the structure uses large area potting, ceramic welding and other new materials and technologies. The structure design of the high voltage power supply module meets the strict requirements of function, maintenance, volume, weight and so on of the power supply in modern airborne transmitter. The high voltage power supply is also verified by sufficient reliability test. The structure design has good stability and maintainability, and can be widely applied in other areas.