The work aims to investigate the influence of pore structure on the mechanical properties and deformation failure modes of foam aluminum. Focusing on homogeneous foam aluminum (L, M, and H) and gradient foam aluminum (LMH), an X-ray computed tomography (X-CT) statistical analysis was conducted to examine the column thickness, pore size distribution, surface porosity, roundness, and fractal dimension of foam aluminum with varying densities. Additionally, numerical simulation methods were applied to analyze the static deformation failure modes of both homogeneous and gradient foam aluminum structures. The results indicated that the column thickness of foam aluminum, across different densities, was predominantly concentrated between 0.2 and 1.0 mm, with approximately one-third of the column thicknesses falling within the range from 0.6 to 0.8 mm. The pore size distribution of foam aluminum was mainly observed to range from 0 to 0.5 mm. Surface porosity was found to be relatively uniform across all directions for foam aluminum with different densities. Under static compression, the deformation failure mode of gradient foam aluminum was characterized by layer collapse, whereas the failure mode of homogeneous foam aluminum primarily involved crack formation in the thin-walled regions of internal cellular pores, followed by the propagation of these cracks to the surrounding areas, ultimately leading to structural failure. In conclusion, the thickness of the struts significantly influences the mechanical properties of aluminum foam. The larger the fractal dimension value of aluminum foam, the more complex its pore structure. Reproducing the compression process of aluminum foam through numerical simulation can provide some reference for the optimization design of gradient aluminum foam.