Abstract: AlSi10Mg Al alloy has the characteristics of low density and high specific strength, which is widely used in aerospace, shipbuilding and other fields. The tensile and impact properties of AlSi10Mg alloy formed by selective laser melting at room temperature were obtained, and the fracture failure modes were discussed. The results show that there is no significant difference in the strength of AlSi10Mg alloy specimens in different directions, while the elongation of the transverse specimen is 25% higher than that of the longitudinal specimen, but the plasticity of both specimens is poor. The tensile fracture characteristics show that the samples in both directions have no obvious necking phenomenon, and both show brittle fracture. The impact toughness of AlSi10Mg alloy at room temperature has obvious anisotropy, and the impact absorption energy of the transverse sample is about 30% higher than that of the longitudinal sample. The impact property of selective laser melting AlSi10Mg alloy is closely related to its reduction of area, and with the increase of ductility, the impact property increases.