Abstract: As a new type of lightweight high-strength materials, the aluminum foam is made based on a new concept of porous metal materials through the formation of air bubbles. In this paper, with consideration of the structural characteristics of the aluminum foam, a bending vibration model of the aluminum foam is built based on the Timoshenko beam theory. With the model, the accurate resonant frequencies and amplitudes are obtained. The analytical results are verified by the results of the finite element modal analysis. From the obtained frequency characteristics of the foam aluminum, it can be seen that the vibration frequency of the aluminum foam used in the field of manned space is far from the base frequency of the manned spacecraft. Finally, the first-order frequency based on the bending vibration model of the aluminum foam is studied by changing the elastic modulus and density. With the increase of the modulus, the first-order frequency increases; on the other hand, with the increase of density, the first-order frequency reduces. Thus by changing the parameters of the aluminum foam, different frequent characteristics of aluminum foam can be obtained, to be used under different conditions of the manned spacecraft.