In the process of large-scale fastener modeling for aircraft structures, the mesh mismatch between fastener endpoints and connected shell elements significantly impacts modeling and analysis efficiency. To address this issue, this paper conducts theoretical research and program implementation focusing on FAST elements. By establishing reference points and adjacent domains, the matching efficiency between FAST element nodes and connected shell elements is improved. The stiffness matrix between fastener endpoints and the constraint matrix between endpoints and connected nodes are derived, resulting in an explicit expression for the FAST element stiffness matrix. Based on this theoretical framework, the FAST element program is developed and integrated into the analysis workflow of the independently developed structural analysis software SABRE. The accuracy of the solution is validated through computational examples of civil aircraft fuselage panel structures.