Civil aircraft use a large number of metal panels. As a typical structural component in the aviation industry, the panel is mainly used to form the fuselage shape and bear various loads transmitted by the fuselage and external aerodynamic loads. It is mainly composed of metal materials such as skin, frame, truss, etc. When the panel structure is subjected to loads such as aerodynamic loads and acoustic loads, static stress and vibration response will be generated. Therefore, its vibration fatigue life must meet the airworthiness requirements. It is of great significance to analyze the vibration fatigue life of metal panel structures under complex loads. Taking typical metal aviation structural parts (panels) as the research object, based on test flight loads, finite element simulation analysis and S-N curves of metal materials, considering the influence of average stress, an improved three-interval random vibration fatigue life analysis method is proposed. Combining load tests, finite element simulations, model correction and other methods, the vibration fatigue life analysis of typical aviation metal structural parts is carried out. The predicted life of this typical aviation structural part is verified to be 866 h by experiments. At the same time, based on the improved three-interval method, the influence of different structural parameters on vibration fatigue life was compared and analyzed. The results show that the improved three-interval method considering the average fatigue stress is reasonable, the calculation results are effective, and it can be used as an engineering treatment method for vibration fatigue life analysis of various metal materials.