Abstract: In consideration of the characteristics of degradation failure for highly reliable,long-life-products,it's difficult to gather enough failure data in limited test period.Research on environment factor based on life failure data is not applicable.The definition and mathematical models of environment factor were proposed based on performance degradation data.The environment factor model for compound Poisson process degradation path was given.For the environment factor,a point estimation method based on quadrature and an interval estimation method based on binomial distribution were proposed,respectively.A numerical example was given to illustrate the efficiency and validity of the methods.