Dynamic deformation and damage of hexagonal aluminium honeycomb sandwich plates subjected to blast loading were investigated experimentally. Different loadings were achieved by changing the mass of Cyclotrimethylene trinitramine (RDX) explosive charge at the same standoff distance. The dynamic deformation and damage patterns of the sandwich plates were obtained and effect of the blast loadings was discussed. New deformation and damage patterns, such as cracking and breaking of the front face sheet, breaking and transverse compressing of the core and perforation of the rear face sheet were observed in experiments. The results show that the deflections of the rear face sheets of sandwich plates increase nearly linearly with blast loadings. The buckling and folding of cell foil of core increase as the blast loadings increase.