Abstract: Semiconductor power devices are used in power conversion fields such as DC, inverter and uninterruptible power supply (UPS) systems and generator excitation systems in nuclear power plants. They are key power conversion power devices with long life, high power, high efficiency, high integration and high reliability. In this paper, the internal structure and aging failure mechanism of insulated-gate bipolar transistor (IGBT) in semiconductor power devices are studied. Based on linear fatigue damage accumulation theory and Arrhenius model, the life of IGBT is predicted by accelerated life test. The typical life prediction model is analyzed and studied with the Coffin-Manson-Arrhenius extensive exponential life prediction model and combined with the operating characteristic parameters of an IGBT used in a nuclear power plant, the life expectancy of the IGBT is scientifically evaluated.