Abstract: For the small suicide unmanned aerial vehicle attacks, the existing storage tanks, command vehicles and other thin shell structures, which are made of steel plate substrate, face serious deficiencies in anti-explosion protection. For this reason, it aims to enhance the anti-explosion performance of thin steel plates using auxetic sandwich honeycomb structure. Based on the riveting-assembly concept, a new double trapezoidal auxetic sandwich honeycomb structure (DT-ASHS) is designed and manufactured on a basis of the traditional double-arrow auxetic sandwich honeycomb structure. According to the theoretical analysis method, the inline relationship is built between the geometric parameters, relative density calculation formula and equivalent Poisson's ratio prediction model of DT-ASHS. Laboratory explosion tests are conducted to assess the anti-explosion mechanical properties of DT-ASHS with varying relative densities and unit-cell layers. Numerical simulations are employed to conduct parametric analyses on the anti-explosion mechanical properties of DT-ASHS. It is found that the compressive deformation of DT-ASHS has a layer-by-layer progressive mode when subjected to explosion loading, and the large enough interfacial riveting force is the key to maintain its deformation in an auxetic deformation state, to ensure that of the continuity of the load transfer and the coordinated deformation. Moreover, too large relative density and core layers of that are not beneficial for the structural compaction, which resulted in lower energy absorption efficiency. In addition, under the design explosion loading, DT-ASHS has a stronger resistance to deformation and load effect dispersion ability compared to its topical non-equilateral hexagonal sandwich honeycomb structure (NE-HSHS), and is also superior to pure aluminum plates and additional-height aluminum plates with the same surface density.