Abstract:As the airborne air conditioner suffers from the variance of nature of the material, structure features, loads applied and stochastic factors, the fatigue life of its structure tends to deviate from the designed life. Based on stochastic finite element method, a mathematic model of the reliability analysis of fatigue life is established about the structure size, damage, fatigue parameters and load. The reliability analysis of fatigue life problem is transformed into the double objective problems of mean and standard deviation of fatigue life, which is balanced through the power factor. The reliability of fatigue life is improved by adopting this method.