The metallized film capacitor is one of the most important types of components of the laser driver in inertial fusion facility.The residual lifetime of the capacitor is of great value in maintenance and spare parts decision making.We used the Wiener process to model the degradation process based on an analysis of the capacitance degradation mechanism of the metallized film capacitor.Taking the inherent difference of each capacitor into consideration

we proposed to use the Wiener process with random effect

where the drift and diffusion parameters of the Wiener process were treated as random variables

whose distribution were estimated using the degradation data from other capacitors from the same batch.When predicting the residual lifetime of a particular capacitor

a Bayesian method was used to integrate its degradation data and the batch information.Posterior distribution of the residual lifetime parameters were deduced.The proposed method can improve the precision of prediction when its degradation data are few.