Closed-cell foamed aluminum alloys were manufactured using selective laser melting (SLM), wherein TiH2 was selected as the foaming agent. The effects of oxidation treatment and content changes of TiH2 on the porosity, pore size distribution and microstructure of the foamed aluminum alloys were studied. The results showed that with increasing TiH2 content, the porosity of the foamed aluminum alloy first increased and then decreased, and the number of pores increased, forming a greater number of micron-sized pores. Moreover, with increasing TiH2 content, the pore size range became more concentrated, and the shape of the pores became more regular. The microhardness value of the manufactured foamed aluminum alloy was between 100 and 130 HV, and the TiH2 content did not have any obvious effects on the hardness value. The results of the compression experiments revealed that the materials manufactured by SLM had energy absorption characteristics and exhibited brittle fracture.