In view of the current problems of bone implants with porous structure, the parametric design, finite element simulation and mechanical testing on negative Poisson′s ratio structures were conducted to investigate the geometric and mechanical characteristics of structures with negative Poisson′s ratio. The research shows that the Poisson′s ratio value for concave hexagon structure with negative Poisson′s ratio is influenced by the geometric parameters of multiple structural cells. It is particularly sensitive to the angle between straight and inclined bars, showing a size effect where larger sizes result in stronger performance. The weight of the structure can be reduced and the porosity can be improved by modifying the conventional concave hexagon structure with negative Poisson′s ratio to the concave hexagon mosaic structure with negative Poisson′s ratio(Embedding a single large cell), but this effect will gradually decrease with the increasing of the number of layers. For the concave hexagonal mosaic structure with negative Poisson′s ratio, the larger cell sizes lead to weaker compressive strength but stronger impact resistance. Furthermore, an increasing of number of cells and layers enhances the compressive strength.