Abstract: Numerical simulation of multi-cell structure and single-cell structure of aluminum foam-filled thin-wall aluminum alloy was conducted by the finite element software LS-DYNA to study their energy absorption capacity. A classical thin-walled tube test and an aluminum-foam-filled thin-walled tube test were numerically simulated. The analysis shows that the numerical model can well simulate the impact force and deformation development of the aluminum-foam-filled thin-walled tube during the axial impact process. Based on this model, the axial energy absorption characteristics of multi-cell structure and single-cell structure of aluminum foam-filled thin-walled aluminum alloy under different factors were compared. Their failure modes, energy absorption mechanism and energy absorption efficiency were analyzed. The results show that the failure mode of aluminum foam-filled thin-walled aluminum alloy exhibits an axisymmetric progressive folding failure mode under the axial impact load. The deformation process is divided into three stages according to the impact-displacement curve and the deformation mode diagram, namely, the elastic stage, the platform stage, and the strengthening stage. When the impact compression distance is 80% of the height of the component, the energy absorption efficiency of the thin-walled aluminum foamed multi-cell structure under seven different parameters is significantly higher than that of the seven single-cell structures. The absorbed energy and the specific energy absorption are increased by more than 50%. It is an excellent energy absorption component and can be widely used in protection engineering.