Journal of Electronic Systems Jing Cao, Meining Zhu, Xuefeng Xing 6 4 2016 http://www.dline.info/jes/fulltext/v6n4/jesv6n4_1.pdf There were two calculation methods of network system reliability: stochastic simulation algorithm and the analytical method. This paper performed stochastic simulation to a certain system on the uncertainty of its reliability degree applying random simulation algorithm and, meanwhile to the probability density distribution, point estimation and confidence interval of the reliability, which has proved the validity of stochastic simulation algorithm when analyzing the reliability and uncertainty of network system. What’s more, the method was verified as capable of getting more information of the system.