Cold standby system was a typical system in area of reliability engineering, which widely reflected the reliability relationship of many engineering structures, and the reliability evaluation of such system is an important research task of system reliability research field. Under actual engineering background ,the switch of cold standby system may not entirely reliable. With type-Ⅱcensored life data of such system, the MLE and Hierarchical Bayesian method were used to estimate the parameters of both switch and working unit, then completed the reliability evaluation of this system. Finally, simulation examples show that Hierarchical Bayesian estimate method is more precise, incidentally, the reliability evaluation method of such system is established with Hierarchical Bayesian method.