Abstract: Aiming at the problem of high-altitude cooling of airborne electronic equipment of high-speed aircraft,a cooling scheme of airborne electronic equipment using liquid water as the main heat sink and antifreeze as the auxiliary heat sink is puts forward.Using the method of combining mathematical theoretical calculation with computer modeling and simulation,the simulation models of main components such as water evaporator and electronic equipment are estab-lished,and the performance of airborne electronic equipment cooling system is analyzed.The results show that at a certain flight altitude,liquid water as the main heat sink can absorb a large amount of heat,meet the temperature control of air-borne electronics,and ensure its stable and efficient operation.