Abstract: Corrugated metal sandwich structures are widely used in high-speed railways, ships, and buildings due to their numerous advantages such as ultra-lightweight, good structural properties (specific stiffness/strength), strong active cooling capacity, and convenience in fabrication and maintenance, etc. However, due to their poor damping characteristics, structural vibration and noise are easily generated under external load excitation. In order to improve the vibration damping characteristics of the corrugated metal sandwich structure and enhance the bearing capacity of the sandwich structure at the same time, we propose the ultra-high molecular weight polyethylene (UHMWPE) to strengthen the corrugated metal sandwich structure, and analyze the effects of the free layer and constrained layer strengthening methods, on the natural frequency and structural damping characteristics of the corrugated sandwich structure. The results show that the damping characteristics of the metal corrugated sandwich structure reinforced with the free and constrained layers of UHMWPE are significantly improved compared with that of the all-metal corrugated sandwich structure.