Abstract: Due to the difference in the manufacturing process of IGBT devices, the lifetime of the IGBT modules is often distributed, whereas the traditional lifetime model based on the analytical method can hardly deal with the problem effectively. In this paper, a prediction method based on the parameter-distributed degradation model is proposed to probabilistically predict the lifetime interval of IGBT modules. First, the reasons for the distribution of IGBT lifetime are analyzed based on the package detects, operating characteristics, and degradation process. Then, the degradation model of IGBT state parameter is established based on the failure evolution law of conduction voltage drop. In the meantime, the distribution characteristics of the model parameters are obtained by the Levenberg-Marquardt algorithm. Finally, the lifetime probability distribution of IGBT modules is predicted by the Monte Carlo method and then verified by experimental examples and additionally compared with traditional models. Results show that the error of predicted average lifetime is around 3% under the consideration of the difference of the same type of IGBT modules. Compared with the traditional lifetime model, the proposed method is superior in predicting the distribution of IGBT lifetime.