Aiming at the problem of fatigue fracture of pipeline connectors, a finite element model of pipeline connectors in aircraft hydraulic system is established. Based on the theory of continuous damage mechanics, the vibration fatigue life of pipeline connectors with assembly stress is predicted. The results show that under normal assembly state, the fatigue crack initiation point of pipeline connectors is located at the contact part between flared conduit and flat nozzle. With the increase of vibration load amplitude, the fatigue life of pipeline connections decreases gradually. When there is axial assembly deviation, due to the influence of stress concentration, the fatigue crack initiation point of pipeline connector is located at the connection between pipe flare and pipe body. The axial assembly deviation weakens the fatigue strength of pipeline connectors. The larger the axial deviation is, the smaller the fatigue life of pipeline structure is.