To those bearings which are used in the field of aerospace, when doing the test of bearing life of the high precision and high reliability, the small sample datas and non-failure phenomenon will occur. To be able to accurately predicting the life and reliability of bearing, the paper analyzes geometry and physics meaning of three parameters of Weibull distribution based on the three parameters Weibull distribution theory. And Builds the Weibull likelihood function. According to Newton iterative method, the left of equations set is expansed to make it transformed into linear equations set. Then iterative calculate the parameters estimate value. So obtain bearing reliability model of three parameters Weibull distribution. Failure statistics shows that the mathematical model of the paper can predict the actual life of bearing.