Abstract: Accelerated life testing (ALT) is a commonly used method in high-reliability and long-life evaluation, and it is adopted widely in life-determination and life-extension of weapon equipment. Based on the existing methods, a new step-down-stress ALT method was brought forward from the assumption that the change in exerting sequence of stress can improve its efficiency greatly. The validity of the method was studied through theoretic model, Monte-Carlo simulation, and contrastive experiment. The results show that step-down-stress ALT method can improve testing efnciency remarkably when applied in wear-out life evaluation.

Key words: systematic evaluation and feasible analysis , accelerated life testing , step-down-stress ALT , reliabili?ty