The balance of temperature distribution across the IGBT insulated gate bipolar transistor module in a motor controller significantly influences the reliability and stability of the system. However the compact design and limited space within motor controllers constrain the application of traditional methods and strategies for temperature balance control. In this context the study investigated control methods to improve the temperature balancing of the heat source by modifying the structural layout of the radiator. Methods The thermal-structure coupling analyses of the traditional structure TypeⅠ structure and TypeⅡ structure of the heat dissipation system were conducted using numericalsimulation methods. The influences of the three structures on the maximum temperature temperature difference and temperature distribution uniformity of the IGBT heat sources were compared and analyzed and the temperature distribution characteristics of the IGBT heat sources within the three structures under different coolant flow conditions were discussed. Results The study indicated that when the coolant flow rate was 2 L / min the maximum temperature differences for the TypeⅠand TypeⅡ structures decreased by 59. 52% and 64. 29% respectively compared with the traditional structure. As the coolant flow rate increased the advantages of TypeⅠ and TypeⅡ structures in controlling the temperature difference of the heat source gradually weakened but they still outperformed the traditional structure. Conclusion Through comparative analysis the TypeⅠ structure exhibits the best uniformity in the temperature distribution of the heat source while the traditional structure has the poorest uniformity. Changes in the coolant flow rate significantly impact the uniformity of the temperature distribution in the traditional structure. As the coolant flow rate increases the average temperature of the heat source in the traditional structure is the lowest and the average temperature in the TypeⅡstructure is the highest. Meanwhile the average temperature of the heat sources in all three structures gradually decreases and the differences between the structures gradually decrease.