Abstract: Aiming at the problem of unclear interface connection performance of the sandwich structure with the core of elastic damping spiral wire mesh, two typical connection processes of vacuum brazing and cementing were adopted. The physical interface bonding mechanism and mechanical properties of the sandwich structure have been studied in-depth through compression and shear tests and microscopic characterizations such as SEM and EDS. The results show that the interface characteristics by brazing process are uniform and continuous rather than that by cementing process. The brazing interface of the sandwich panel has formed a good metallurgical bond, i.e., the Ni and Si elements in the brazing filler metal diffuse obviously with the Fe and Cr elements in the panel and core material. The highest loss factors of the brazed sandwich panel and the cemented sandwich panel under the static compression load can reach 0.194 and 0.128, respectively. This means that the sandwich panel with metal spiral mesh has a large energy dissipation capacity. The peak loads of tensile shear test for the brazed cemented sandwich panels are up to 2 589 N and 1 302 N, respectively. The peak load of the former increases with the increase of the core material density, while the latter is the opposite. The failure mode of the brazed sandwich panel in the tensile shear experiment is peeling of the panel and the core material, while the cemented sandwich panel mainly occurs crack propagation and fracture of core material. This research provides a theoretical and application guideline for the connection and mechanical performance analysis of porous metallic sandwich structures.