The characteristics of electromagnetic design and structural design of synchronous generator for high voltage frequency converter were introduced. Based on the twodimensional timedomain finite element method, the electromagnetic characteristics of the two electrical machinery, such as harmonic distribution, air gap magnetic field time distribution, and the starting process of the damping ring, were calculated and analyzed. The feasibility of the design scheme was verified by the analysis of the motor type test of the synchronous generator, which laid the foundation for the further application of this kind of high voltage synchronous generator set in the field of high voltage frequency converter.