problem to predict the fatigue life of structures subjected to random loads. The simplest and most widely used damage model is the Miner's linear damage criterion. However, the application of this criterion often leads to the risky life prediction. Nonlinear cumulative damage theory takes into account the effect of loading sequence on fatigue life, with higher accuracy, but it is cumbersome and can not be used for frequency domain life calculation. In this paper, a modified algorithm of frequency domain fatigue life prediction based on nonlinear cumulative damage is presented. The accuracy of the algorithm is verified by simple test. For a stiffened plate structure with accurate dynamics modeling, the validity of the method and the engineering usability are proved.