A tensile test was conducted on a composite stringer run-out specimen incorporating crack-arresting fasteners. Using the ABAQUS platform, finite element models were developed to simulate pre-existing debonding at the stringer-skin interface within the bolted run-out region. The bolted reinforcement area was modeled using GBJM (global bolted joint model). The influence of the pre-debonded area on interface damage initiation and the structure’s load-carrying capacity were analyzed. Furthermore, the load transfer mechanism of the arrest fasteners during structural failure was investigated. The results indicate that interface failure in the stringer run-out under tensile loading results from the combined action of out-of-plane peel stress and interlaminar shear stress. Fasteners located in the intact region of the stringer-skin interface carry negligible load. However, once debonding occurs, these fasteners begin to engage and transfer load. The extent of the bonded area at the stringer-skin interface primarily affects the damage initiation load but has little influence on the ultimate failure load of the structure. The first fastener row acts as the primary load-bearing element, upon failure of the structure surrounding its bolt holes, the load it carries drops sharply, accompanied by a significant increase in the load transferred by the second fastener row.