For the problem of fatigue failure on of bolt in random vibration test, the random vibration fatigue life is estimated by finite element method. The method is based on the information of the frequency domain of random loading history. In this paper, bolts are simulated by rigid connection. Firstly, the stress transfer function of the structure is analyzed by frequency response simulation, obtained peaks per second of the bolt. Secondly, the force of bolt was picked. Thirdly, the stress of bolt was calculated. Combined with S-N curve of 17-4PH and fatigue damage accumulation theory, random vibration fatigue life of bolt is analyzed by Three-band method.