The actuator for the control surface of air vehicle wing controls aircraft"s position and plays the important role of the aircraft stability. Compact and light-weight with stability is very important for avionics system. Actuator and controller are integrated for the lightweight and compact system, but electrical components"s increasing installed in limited size results in increasing thermal density. In this paper, thermal simulation was performed using ANSYS ICEPAK for the thermal reliability analysis of integrated electro-mechanical actuator.