Abstract: The pendulum bob and platform crash tests for designed aluminum alloy car bumper beam with thin-wall, hollow cross section and strengthening rib simulated by the finite element analysis software-LSDYNA, some revevant tests were performed and the crash properties of the aluminum alloy beam was compared with that of the steel beam. The results show that the finite element results and factual test results for platform tests fit well at low-speed of 20 km·h-1. Comparing with the steel beam, the aluminum one bad better stiffness and energy absorption property. Under the same crash test conditions, the energy absorption property of the steel beam was limited, while the aluminum alloy beam could maintain higher energy absorption property in a larger speed-range.