As an alloy suitable for selective laser melting (SLM) process, rare earth elements doped aluminum alloy has been widely used due to its superior mechanical properties and good formability. The forming quality is determined by the processing parameters. In this paper, by controlling key process parameters such as laser power, scanning velocity and hatch spacing, the evolution of relative density and defect types of SLM rare earth elements doped aluminum alloys at different process parameters are studied. The results show that changes in process parameters will lead to changes in energy density, the relative density of the alloy is affected by the volumetric energy density and the liner energy density of the single pass. When the volumetric energy density is 70-180 J/mm3 and the liner energy density is 0.250-0.525 J/mm, the relative density of the alloy is stable above 99.5%.