High-frequency digital inverter power supply has the advantages of small, no noise, high efficiency, small ripp- le, and perfect protection, therefore, is gradually replacing the traditional electron beam welder which uses the 400Hz frequency generator. However, with more high frequency of the power supply, the design of the transformer used by the high-frequency high-voltage electron beam welding becomes difficult. Therefore, this paper put forward a diversified transformer mode and a voltage doubling rectifier circuit, which were used to reduce the transformer turns ratio, thus reducing the topology of the transformer distribution para- meters. Accordingly, a special high-frequency high-voltage electron beam welding tank is designed. Tests show that the set of performance indicators of the fuel tank meets the design goals to meet the actual needs of welding process.