Aluminum alloy has the characteristics of low density, high specific strength and good corrosion resistance, which can well meet the lightweight needs of aerospace vehicles, and the aluminum alloy parts manufactured by selective laser melting (SLM) technology have good comprehensive properties and have been widely used in the aerospace field. However, there are some problems in the forming process, such as poor defect control, poor surface quality, cumbersome post-treatment process and so on. This paper selects AlSi10Mg aluminum alloy fabricated by SLM to conduct a solid process optimization study for defect elimination, in order to obtain the optimized process parameters with the least defects and further study the surface roughness optimization method. Results show that lower porosity (9.2%) and better internal forming quality can be obtained by optimizing the process parameters (mainly including scanning power, scanning speed, scanning spacing). The main influencing factors of the surface quality of the formed parts are scanning power, scanning speed, scanning spacing, etc. It is found that appropriately increasing the scanning power can obtain better surface quality.