In the context of severe global environmental issues, new energy vehicles have become an important strategic direction for countries to promote green travel with low carbon emissions. The electric drive system is the core power source of new energy vehicles. Among them, the motor controller is extremely important, and IGBT is the core component of the drive motor controller. IGBT is composed of BJT and MOS. When the battery discharges to drive the motor, it converts direct current into alternating current and controls the alternating current motor. The IGBT module generates a large amount of heat during operation. An increase in temperature will increase the failure probability, affect performance and reduce the working life. Based on the CFD method, this paper uses Fluent software to study the heat dissipation process of traditional IGBT, analyzes the internal flow field and temperature field, provides data support and technical support for the development of a new high-efficiency heat dissipation system, and is of great significance for promoting the development of new energy electric vehicles.