In order to meet the design demand of the thermal protection and thermal management system for electronic equipment in aircraft engine nacelle, in this paper, the heat generation and transmission process inside the engine nacelle was analyzed, the equilibrium equation was obtained, the heat calculate methods of the relevant parts related to electronic equipment was proposed, and the heat transfer calculation model of electronic equipment in engine nacelle was established. Using this calculation model, the steady thermal transmission of an electronic equipment in aircraft engine nacelle under typical working conditions was analyzed by iterative computing. The results shows that, comparing with the temperature of air in engine nacelle, the temperature of engine casing has a greater influence on the heat transmitted into the electronic equipment. The results shows that the higher the surface emissivity of the insulating material, the higher the equilibrium temperature of the surface of the insulating material, and the more heat will be transferred into the interior of the electronic equipment.