Abstract: In order to enhance the mechanical behavior of ultra-light lattice composite structure with high strength, especially its anti-buckling ability, a new hierarchical isogrid sandwich structure was designed. An equivalent continuum method was proposed to put forward the equivalent calculation theory of hierarchical isogrid sandwich plate and to predict the effective elastic modulus and bending rigidity of the stretching-dominated hierarchical structure. Elastic buckling failure load and strength in material failure mode of the hierarchical isogrid sandwich plate in edgewise compression were analyzed. Based on these theoretical models, failure mode map of the hierarchical isogrid sandwich plate under edgewise compression was plotted to point out the corresponding relationships between the structure failure modes and the dimensions of the hierarchical isogrid sandwich plate. Results show that hierarchical isogrid sandwich plate with I-shaped cross-section is stiffer and stronger in buckling resistance compared with isogrid plate with traditional rectangular cross-section. The property of hierarchical isogrid sandwich plate is superior as a kind of ultra-light lattice structure with high strength.