In order to effectively evaluate the reliability of ammunition, the classical method and Bayes method of reliability evaluation assessment of success or failure components are introduced. The 3 conjugate prior used for find the lower confidence limit of reliability is proposed for reliability evaluation of ammunition components with no-prior information. And the influence of commonly used conjugate prior distribution on the lower confidence limit of reliability and the application of each conjugate prior distribution are obtained by numerical simulation analysis. The results show that the 3 conjugate prior distributions is more appropriate and can provide support for improving the accuracy of the reliability evaluation ammunition.