As the core component of the flexible DC converter valve, the performance of the high-voltage and high-power press-pack IGBT module directly affects the safe and reliable operation of the converter system. However, the flexible DC converter valve sub-module adopts multi-module stacking series and multi-chip parallel connection to improve the voltage and current level, and its structural characteristics lead to the difference of distribution parameters in the module, and it is of great significance to study the non-uniform electrical stress distribution of IGBT module under the influence of distribution parameter differences. In this paper, the differences in the distribution parameters caused by the asymmetry of the IGBT multi-module stacking sub-modules are analyzed, and the distribution parameters of the press-pack IGBT modules are extracted. Secondly, the multi-chip parallel equivalent circuit model of IGBT module is established, and the uneven electrical stress distribution under the influence of parasitic inductance and parasitic resistance distribution parameters is analyzed, and the accuracy of the equivalent circuit model is verified by datasheet comparison. Finally, the electromagnetic field finite element model of the IGBT module is established, and the simulation results further verify the effectiveness of the equivalent circuit model.