Porous sandwich structures are widely used in anti-explosion due to their excellent specific strength and stiffness. However, current explosion research mainly focuses on the failure mechanism of sandwich structures under small equivalent explosion loading. In contrast, the research on energy absorption characteristics of porous sandwich structures under actual large equivalent loading is rarely reported. To better guide the engineering application, ten kinds of sandwich structures with three kinds of sandwich materials (foam aluminum and honeycomb aluminum with 3 mm×10 mm side length) under different sandwich configurations (single-layer and two-layer sandwiches) and different thicknesses of face sheet/middle sheet/rear sheet were designed. The explosion tests with 0.5 kg TNT and 1 kg TNT equivalent explosion loading were respectively carried out on the above sandwich structures, and the overall deformation characteristics of the sandwich structures were analyzed. The effects of sandwich materials, sandwich configurations and other factors on energy absorption were discussed. Results show that both the foam sandwich structure and honeycomb sandwich structure could absorb energy through the large compression deformation of core material under explosion loading, while the deformation uniformity of the honeycomb structures is better. Furthermore, the energy absorption efficiency of the core is both related to its specific compressive strength and strength/stiffness of the face sheet/rear sheet. It is quite necessary to optimize those parameters to ensure that the core material can obtain a maximum compression and give full play to its energy absorption advantage. It is also found that the double-layer sandwich structure is superior to the single-layer sandwich structure on energy absorption and protection performance, which is an effective way to improve the overall energy absorption of the structure.