Failure Mode Effect and Critically Analysis(FMECA) is one of the key technologies in testability verification test that based on plenty of failure samples.Line replaceable module(LRM) is the core of the new generation avionics system and military equipment electronic system. Failure data of LRM is difficult to acquire under natural conditions,however,it could be obtained fleetly through accelerated degradation test(ADT).According to the degradation data obtained from the accelerated degradation test and the degradation model, the typical failure modes and the occurrence probability of the LRM could be obtained.