Selective Laser Melting (SLM) is an additive manufacturing technology that is based on melting layers of metal powder using powerful laser without traditional limits. Considering efficiency, cost and stability, some specific rules should be complied with in process of the structure design. In this article, SLM specialty of the aero aluminum alloy support was analyzed including total time, expenditure, difficulty in post-process and stability. Then the original structure was redesigned combined with SLM specialty. Complex of the structure was studied involving performance and SLM manufacturing.An optimal structure was obtained that the weight reduced by 24.5%, weighting stiffness increased by 38.3%, displacement reduced by 32.7% at most. Total time evaluated reduced by 38.6%, material consumption reduced by 65.6% dramatically at scale coefficient of 0.5. There were no supports inside the optimal structure, the post-process was easier, and fabricating stability was significantly improved.