As a crucial interconnecting element within the tunnel infrastructure, the tunnel-working shaft structure is integral to the tunnel's normal operational functionality and the assurance of its safety. The present study investigates the seismic performance of a shield tunnel-working shaft structure in a complex geological environment, both before and after the implementation of end reinforcement measures. Furthermore, given that the tunnel is situated in an area characterized by high seismic activity, the implementation of seismic damping measures is imperative. In this study, flexible nodes are combined with shape memory alloys (SMA) to propose an SMA damping device, which is then subjected to an experimental study..Based on the test outcomes, the proposed SMA damping devices has been integrated into the numerical model of the tunnel-working shaft structure. This integration allows for an investigation into the damping mechanism of the SMA damping devices and its damping impact on the tunnel-working shaft structure, as well as a discussion on the seismic response law of the tunnel-shaft structure when employing the SMA damping devices. In light of the proposed damping mechanism of the SMA damping device, it offers a novel approach to seismic damping measures for tunnelworking shaft structures in challenging geological environments.