In accelerated degradation test, it is essential to establish a suitable degradation path model of the component. In order to predict the life accurately, it is critical to determine the sensitive parameters. A degradation path modeling method based on time series analysis was proposed in this paper. The sensitive parameters were determined by time series stationary test, and a time series ARIMA model was established for the degradation of sensitive parameters. Taking TL431 as an example, the accelerated degradation tests were carried out to investigate the degradation of its performance parameters, and a degradation path model was established for the parameters. The results indicate that the proposed method is feasible for accelerated degradation test.