Abstract: Contamination caused by stirling cryocooler outgassing becomes a crucial factor that impacts cryocooler´s life.Concaminants in cryocooler will leads to the rubbing of mechanical parts or blockage of flow，which in turn reduces cooler life and/or degrades performance.Accelerated lifetime evaluation technique and numerical analytical methods were introduced.Some suggestions and techniques about cryoclooler contamination failure were discussed.