Abstract: The continuous development of flexible High Voltage Direct Current (HVDC) transmission system poses more requirements to the insulated gate bipolar transistor (IGBT) devices. Press Pack IGBTs (PPI) are valued for their development demand of high voltage, high current and high power in the areas of flexible HVDC transmission system. At present, two types of Press Pack IGBTs with pedestal structure represented by WESTCODE and TOSHIBA as well as Stakpak structure represented by ABB, have been successfully applied in the flexible HVDC transmission projects. These two kinds of structural models of the Press Pack IGBTs based on finite element method are established. The pressure distributions within these two kinds of Press-Pack IGBTs in normal pressurization conditions and normal working conditions are analyzed. The simulation results show that the pressure distributions within both types of Press-Pack IGBTs in normal pressurization conditions are relatively uniform, while the pressure distribution of the stakpak structure is more uniform in normal working conditions. Finally, based on the simulation results, this paper proposes possible solutions to the structural optimization of the Press Pack IGBTs.