Laser shock strengthening can enhance the surface strength of aircraft engines and enhance material toughness. However, aviation engines are in a complex working environment, and their fatigue life is influenced by multiple factors. Especially the significant changes in material performance parameters after laser shock strengthening, which increases the difficulty of measuring the fatigue life of aviation engines. Therefore, a precise measurement method for the fatigue life of aviation engines after laser shock strengthening is proposed. Firstly, analyze the working principle of laser shock strengthening for aircraft engines, and establish a fatigue damage function for aircraft engines based on fatigue damage theory and Von-Mises yield criterion. Then, combined with the fatigue damage function and grey correlation analysis method, weight analysis was conducted on multiple factors that affect the fatigue life of the aircraft engine to obtain the fatigue index of the aircraft engine, thereby achieving accurate measurement of the fatigue life of the aircraft engine. The experimental results show that the proposed method can achieve precise monitoring of the fatigue life degradation trajectory of aircraft engines, and can accurately analyze the distribution of engine surface fatigue life, indicating that the method's fatigue life measurement results are more accurate.