Abstract: Aiming at the problems of low ultimate bearing capacity of traditional grid sandwich structure and easy condensation of water vapor caused by single cell sealing, a cross-locked grid sandwich structure was proposed based on analyzing the microstructure and function of tracheids. Firstly, the minimum volume (minimum mass) and minimum deformation (maximum stiffness) were selected as the optimization objectives, and the second generation non-dominated genetic algorithm (NSGA-II) was used to complete the multi-objective optimization. The three-dimensional Hashin failure criterion and the improved stiffness degradation method were used to establish the finite element analysis model of progressive impact damage for the grated sandwich plate. The failure mechanism and mechanical response of a variety of low speed impact loads to different positions of sandwich structures with different relative densities were studied. Results show that the new type of sandwich structure shows good shock impedance at low speed. Its differences with the core of the spatial distribution, the shock resistance of grille gaps are weaker. Core density increase cannot effectively improve the impact strength of the location. The sandwich structure is much larger than all the damage by impact grid intersection point of the device. Under the influence of different impact location and impact velocity, load-time and displacement-time curves show different typical patterns. The failure of core appears, such as buckling, delamination, bonding stripping and bending deformation, and mixed damage occurs on the front panel of composite material. With the increase of impact velocity, the damage degree of core and panel becomes more serious.