This paper develops a new method of parametric estimate, which is named as “synthesized expected Bayesian method”. When samples of products are tested and no failure events occur, the definition of expected Bayesian estimate is introduced and the estimates of failure probability and failure rate are provided. After some failure information is introduced by making an extra-test, a synthesized expected Bayesian method is defined and used to estimate failure probability, failure rate and some other parameters in exponential distribution and Weibull distribution of populations. Finally, calculations are performed according to practical problems, which show that the synthesized expected Bayesian method is feasible and easy to operate. This paper develops a new method of parametric estimate, which is named as “synthesized expected Bayesian method”. When samples of products are tested and no failure events occur, the definition of expected Bayesian estimate is introduced and the estimates of failure probability and failure rate are provided. After some failure information is introduced by making an extra-test, a synthesized expected Bayesian method is defined and used to estimate failure probability, failure rate and some other parameters in exponential distribution and Weibull distribution of populations. Finally, calculations are performed according to practical problems, which show that the synthesized expected Bayesian method is feasible and easy to operate.