In order to study the time over the highest temperature can be tolerated (over temperature time) in certain working condition, the lumped parameter method was used to analyze the transient heat transfer of actuator solenoid-valve of aero engine vectoring nozzle. The totally actuator solenoid-valve shell and actuator solenoid-valve parts were studied as research object, respectively. The mathematical model of the temperature and time of the actuator was established, considering the convective heat transfer and radiation heat transfer between the actuator solenoid-valve and the environment. The influence of Twai and T0 on the model was studied. The results show that: the temperature of the actuator solenoid-valve increase with the increase of environmental temperature, the over temperature time decrease with the increase of environmental temperature. In the same heating time and environmental temperature,the temperature of actuator solenoid-valve parts far higher than the temperature of actuator solenoid-valve shell. When the Twai is 250℃ and the T0 is 70℃, the over temperature time of actuator solenoid-valve parts is 17 minutes, the over temperature time of actuator solenoid-valve shell is 59 minutes. When the Twai is 250℃ and the T0 is 93.76℃, the over temperature time of actuator solenoid-valve parts is 15 minutes, the over temperature time of actuator solenoid-valve shell is 50 minutes.