The work aims to prepare aluminum foam-polyurethane composites and study the effect of porosity and polyurethane (PU) content of spherical open-cell aluminum foam on the compression and energy absorption properties of aluminum foam-polyurethane composites, and analyze the law of effects of porosity and polyurethane content of aluminum foam on the energy absorption efficiency and ideal energy absorption efficiency of aluminum foam-polyurethane composites. The specimens of composites were subject to a quasi-static compression test to obtain the corresponding stress-strain curves, and the energy absorption-strain curve, energy absorption efficiency-stress curve and ideal energy absorption efficiency-stress curve were further derived. When the porosity of the aluminum foam was constant, the compression and energy absorption properties of aluminum foam-polyurethane composites were improved with the increase of PU content. When the PU content was constant, the compression and energy absorption properties of the aluminum foam-polyurethane composites would increase as the porosity of the aluminum foam decreased. The application range of the energy absorption efficiency curve and the ideal energy absorption efficiency curve is clarified, which provides a basis for the selection of buffer materials.