Foam metal is often subjected to dynamic loads in practical engineering applications, which is multicellular material structure, and its optimal structure design needs to be based on its mechanical properties under dynamic and static loading conditions. Therefore, aiming at the problem that the dynamic properties of foam metal could not be simply characterized by the static loading properties, the numerical simulation experiments were carried out on the uniaxial dynamic tensile of foam metal based on the dog bone-shaped specimen model established by 3D Voronoi. Then, the influences of loading strain rate, relative density and shape irregularity parameters on the dynamic properties of foam metal were quantitatively studied, and the microscopic deformation characteristics were observed. The failure mechanism was expounded, and the influence of inertia stress was eliminated by quantifying the inertia effect under high speed tensile loading to study the uniaxial dynamic tensile failure performance of foam metal. The results show that both the relative density parameters and shape irregularity parameters have significant effects on the failure stress and failure strain of foam metal in dynamic tensile. The failure modes of foam metal under different strain rates are also different, but have little effect on the stress-strain curves of the model.