The work aims to study the effect of aluminum foam’s relative density, polyurethane content and polyurethane mass fraction of the hard segment (the mass fraction of hard segment occupying the thermoplastic polyurethane elastomer rubber) on the mechanical properties of aluminum foam-polyurethane composites. The aluminum foam-polyurethane composites were self-prepared. The quasi-static compression experiments were carried out on the aluminum foam-polyurethane samples prepared. Through the quasi-static compression experiment, the stress-strain curves respectively corresponding to the relative density, polyurethane content and polyurethane mass fraction of the hard segment of different aluminum foams were obtained. From the analysis, the relative density of aluminum foam was increased from 5.4% to 6.1%, the yield strength of aluminum foam-polyurethane was increased by 12.8% and the flow stress was increased by 29.8% when the polyurethane mass fraction of the hard segment and the polyurethane content were constant. The polyurethane content was increased from 9.21 g to 13.19 g, the aluminum foam-polyurethane yield strength was increased by 32.6% and the flow stress was increased by 10.9% when the polyurethane mass fraction of the hard segment and the relative density of the aluminum foam were constant. Based on the stress-strain curves in the results, the relative density of different aluminum foams, polyurethane content and polyurethane mass fraction of the hard segment are positively correlated with the mechanical properties of aluminum foam-polyurethane composites. The relative density of aluminum foam, the polyurethane content, the polyurethane mass fraction of the hard segment and the buffer energy-absorption characteristics of aluminum foam-polyurethane composites are positively correlated.