To improve the accuracy of storage reliability analysis for the explosive initiator, the sensitivity test was studied and the storage reliability analysis for explosive initiator was proposed using the sensitivity test data. In the method, the estimations of sensitivity distribution parameters were obtained from the up-down test data, and were processed to be order restriction with the isotonic regression. Then using the order restriction estimations, the model was established to relate the sensitivity distribution to storage time. Using the model, the confidence interval of storage reliability and storage life were obtained. The illustrative example shows that the method is available for storage reliability assessment or storage life prediction on the explosive initiator with high reliability.