Abstract: With the increasing of integration degree and power of chips, problems concerning the thermal design of modular electronic equipment become more and more serious. In this paper, thermal design is conducted for a servo control module using Icepak. Based on thermal analysis theory, cooling fins are machined on the module, and then the influence of different fin thickness and fin spacing on temperature distribution is analyzed. Finally, the thermal design which meets the temperature requirements and machining requirements is obtained. Results show that cooling fins can effectively reduce overall temperature of the module without needing additional cooling device and increasing module size. The analysis method in this paper could provide a reference for the thermal design of modular electronic equipment.