Abstract: In order to meet the requirement of high explosive train of fuze for high reliable and safe priming and boosters, the output and shock wave sensitivity of PBXN-5 booster were analyzed and studied by small-gap test and rise-and-fall method. The small sample testing indicates that the probability of reliable booster will reduce obviously with the increment of the gap thickness between the donor and the accepter when the donor charge keeps constantly;but the probability of reliable booster will rise with the diameter of accepter charge decreasing. In a word, the usage reliability will be higher with the decrease of diameter of accepter charge and gap thickness. By combining the usage security, the proper reliable parameters for charge in micro initiators & pyrotechnics will be obtained.