Abstract: Aiming at the fracture failure of the clamps used in the external pipeline system of aero engines during service, failure analysis was carried out on the external pipeline system. Macroscopic observation on fracture position, macroscopic and microscopic observation on fracture surface, and energy spectrum analysis were carried out. In addition, after adjusting the length of the clamp gasket, and the installation torque and R-angle size of the clamp, vibration fatigue tests and finite element analysis were conducted to determine the fracture mode and cause of the clamps. The results show that the fracture mode of the clamps is fatigue fracture. The additional stress caused by non-standard installation of the clamps, combined with vibration stress, resulted in micro-cracks, and the cracks propagated, leading to fracture. Two improvement measures were proposed to enhance the service life of the clamps: optimizing the tightening process and optimizing the structural design. The tightening torque and optimal R-angle size of the clamps were determined based on vibration fatigue testing and finite element simulation, and were verified by experiments. The fatigue vibration resistance time of the improved clamps has been significantly increased, and the reliability of the clamps during service in aero engines has also been greatly enhanced.