In the design realm of fusion power supplies, structural component plays a pivotal role in ensuring the safety of fusion device. To verify the reliability of converter structure design in Comprehensive Research Facility for Fusion Technology (CRAFT), the meticulous analysis of the converter's dynamic impact is carefully analyzed based on the worst fault current (400 kA), firstly. Subsequently, the thermal stress analysis based on maximum allowable steady-state temperature is finished, and the equivalent thermal stress, thermal deformation, maximum shear stress of single bridge arm and whole converter are studied. Furthermore, a simple research method of current sharing characteristics of bridge arm with multi-thyristor parallel connection is proposed by combination Simplorer with Q3D in ANSYS. The results show that the current sharing characteristics is great. Finally, the structural design has been meticulously tailored to meet the established requirements.