Abstract: In the practical application of composite materials, using the failure of assembly components or faste-ners as a criterion for determining the failure of composite bolted joints brings great risks. After analysis of development characteristics of fatigue damage in composite materials, a method for predicting the fatigue life of composite bolted joints was proposed, which was based on the deformation of connection holes, and validated by using experimental data on tensile-tensile fatigue performance of double-bolt single-lap and single-bolt double-lap composite joints. The results show that the deformation of the connection hole can well reflect the development process of fatigue damage of the connection structure, and the maximum relative error of the fatigue life prediction model proposed in this paper does not exceed −3.62%. The existence of assembly gaps can lead to a decrease in the fatigue life of the connection member of up to 64.8%.