Fatigue life scatter factor of aircraft damaged structures is an important parameter to analyze the fatigue life dispersion degree of damaged structures. In this paper, the fatigue test of prefabricated damage test pieces is carried out for aluminum alloy materials commonly used in aircraft. The distribution type of residual fatigue life of damaged structures is determined by correlation coefficient comparison method. The relationship between damage and fatigue life and the dispersion of residual fatigue life of damaged structures were analyzed through fracture observation and statistical data processing. The results show that the residual fatigue life of damaged structures is consistent with Weibull distribution. The fatigue life of the structure with preset damage decreases obviously compared with that without preset damage, and the residual fatigue life of the structure decreases gradually with the increase of preset damage size. With the increase of the preset damage size, the residual fatigue life dispersion increases, and the fatigue life dispersion of different structures with initial crack damage is different. The work in this paper provides a reference for establishing fatigue life scatter factor models of aluminum alloy structures with different damage sizes.