The invention provides a method and device for evaluating the reliability of an IGBT device in a high-voltage direct-current circuit breaker. substituting the obtained capacitance discharge curve andthe obtained current curve of the IGBT device flowing through the semiconductor module into a pre-constructed simulation model respectively to obtain evaluation parameters of the IGBT device in the semiconductor unit and the semiconductor module respectively; evaluating the reliability of the IGBT device in the semiconductor module based on the evaluation parameters of the IGBT device in the semiconductor unit and the evaluation parameters of the IGBT device in the semiconductor module; wherein the evaluation parameters comprise a junction temperature curve, a turn-off time and a highest junction temperature, and the simulation model comprises a semiconductor unit. The obtained reliability assessment result is high in accuracy; the junction temperature and current values of the IGBT devicein the simulation model at the turn-off moment and the junction temperature and current values of the IGBT device in the DC circuit breaker at the turn-off moment under actual working conditions canbe accurately reflected; the method provides a basis for verifying whether the IGBT device in the direct current circuit breaker can meet the requirements of special working conditions of the direct current circuit breaker, and is simple, easy to implement and easy to implement.