The premise of predicting storage life from accelerated storage test data is the consistency of failure mechanism between use condition and raised stresses. Nonparametric consistent test method for accelerated storage degradation failure mechanism was proposed based on Spearman rank correlation coefficient.If the failure mechanism is consistent in different stresses

the shape of the degradation path is the same.This is essential to consistent test.The Spearman rank correlation coefficient was proposed to measure the difference of the curve shape in different stresses.At last

two examples were given to illustrate the validity of the method.