Abstract: The flexible damping technology has been extensively acknowledged as an application for seismic damage reduction in underground engineering projects. To further develop and implement this technology, a viscoelastic damping layer structure is proposed based on the understanding of viscoelastic damping theory in the field of seismic resistance of bridge construction. An improved spilt hopkinson pressure bar (SHPB) test system is used to perform the impact tests on different rock-damping layer-concrete specimens. The energy absorption laws using different damping layer materials (rubber and silicone) and different damping layer structures (honeycomb, corrugated and cylindrical) are comparatively studied. At the same time, with the same layer material and structure of the damping layer, the energy absorption laws of the structures with different thicknesses of damping layer are compared and analyzed, and the optimal thickness is investigated. The results show that the incident energy absorbed by the damping layer structures of different damping layers has increased by more than 10%, compared to the control group (rock-concrete specimen). It is indicated that the structure has superior energy absorption characteristics and the rubber can absorb more incident energy as the damping layer than the high-damping silicone. Among various damping layer shapes, the composite damping layer structure with a honeycomb damping layer has better energy absorption characteristics than the others. In addition, after comparing and analyzing the energy absorption effects of the structures with different thicknesses of the damping layer, it is found that the optimal thickness of the damping layer with the best energy absorption effect is 20 mm. The overall results can serve as a theoretical and data support for the application of composite damping layer structures in seismic design of underground engineering projects.