Abstract: According to the fact that the fatigue life of hydraulic pipes with different diameters designed by flow rate can not meet the requirements, the influence of random vibration on the fatigue life of aviation hydraulic pipes with different diameters and wall thickness was analyzed. The pipe model was simplified. The modal analysis and random vibration response analysis were carried out. The fatigue life time under different pipe diameters and wall thickness was obtained by combining fatigue damage accumulation theory and S-N curve of material. The results show that the larger the pipe diameter and wall thickness, the greater the impact on the fatigue life time.