Abstract: IGBT components are widely used in converters, inverters, power transmission, and so on. With the continuous increasing of their heat consumption and volumetric power density, the quality of their thermal design is directly related to the operation stability, reliability and service life. In this paper, the 3D composite heat pipe radiator applied to IGBT module cooling system is studied, its structure and working principle are presented in detail. A full assessment of its application advantages is performed through numerical simulation and experimental verification. The heat pipe radiator in a limited structure space is able to control the temperature of the IGBT module with very high power density very well, so that the device can operate safely and stably for a long time, and the products reliability is improved.