Abstract: Insulated gate bipolar transistor（IGBT） modules have become the most fragile component in electric vehicle drive systems due to the harsh operating environment. The failure of the relevant power module is mainly caused by temperature-related factors. To predict the chip junction temperature as accurately as possible, a compact thermal network model suitable for the thermal analysis of electric vehicles was proposed. The finite element model of IGBT modules containing a water-cooled system was built in ANSYS/ICEPAK firstly. Then a 3 D compact thermal network model considering the thermal coupling of the upper and lower bridge arms was proposed and the steps of parameter extraction of the thermal network model were described in detail. Finally, the simulation results of the 3 D thermal network model are in good agreement with the finite element simulation model. and experimental results shows that the proposed thermal network model can accurately predict the junction temperature of power module in electric vehicles. Compared with the finite element model, the proposed thermal network model reduces simulation time and is suitable for lifetime estimation and on-line junction temperature prediction for power module.