Abstract: The high energy density selfhealing metallized film pulse capacitor has been applied to all kinds of laser facilities for their power conditioning systems, whose reliability and expense are straightforwardly affected by the reliability level of the capacitors. Based on the related research in literature, this paper analyses the degradation mechanism of the capacitor, and presents a new degradation failure model-the Gauss-Poisson model．The Guass-Poisson model divides degradation of capacitor into naturalness degradation and outburst one.Compared with traditional weibull failure model, the new model is more precise in evaluating the lifetime of the capacitor, and the life tests for this model are simple in design, and lower in the cost of time or expense．The GaussPoisson model will be