The work aims to study effects of relative density and pore size of foamed aluminum on quasi-static compression mechanical properties, the energy absorption properties, the energy absorption efficiency and the ideal energy absorption efficiency of the aluminum foam-polyurethane composites. The prepared aluminum foamed- polyurethane composite were subjected to quasi-static compression experiments on a universal material testing machine and the corresponding curves of the stress-stain were obtained. The energy absorption properties, the energy absorption efficiency and the ideal energy absorption efficiency of materials were analyzed by the corresponding curves of the stress-strain. When the pore size of aluminum foam was constant, the relative density of aluminum foam was increased from 0.350 to 0.384; and the yield strength of aluminum foam-polyurethane composites was increased by 4.38 MPa. The quasi-static compression performance was improved, but the maximum energy absorption efficiency was decreased from 0.29 to 0.27. When the relative density of aluminum foam was constant, and the pore size of aluminum foam was increased from 5 mm to 9 mm; the yield strength of aluminum foam-polyurethane composites was increased by 6.16 MPa; the maximum energy absorption efficiency was increased from 0.25 to 0.27 and the quasi-static com-pression performance was improved. When performing quasi-static compression, the compression properties of the aluminum-polyurethane foam composites is increased with the increasing of the relative density and the pore size; the energy absorption properties of the aluminum-polyurethane foam composites is increased with the increasing of the relative density and the pore size. The maximum energy absorption efficiency is decreased with the increasing of the relative density, and changed slightly with the increasing of the pore size.