High-performance aluminum alloys have broad application prospects in the fields of aerospace, vehicle engineering, and ocean engineering due to its light weight, high strength, and excellent corrosion resistance. However, as the shapes and structures of aluminum alloy parts become more and more complex, traditional forming processes are difficult to meet the demand. Selective laser melting (SLM) technology is in capability of integrated forming of complex shapes and precision parts. Therefore, SLM technology has great development potentials in aluminum alloy forming. However, due to its wide crystallization and solidification range, high laser reflectivity and high thermal conductivity, aluminum alloy is prone to generate defects during SLM forming process. It would result in a decline in mechanical properties of aluminum alloy parts. In order to solve these problems, researchers have done a lot of work and made some progress in recent years. Based on this, the main defects and their forming mechanism of SLM-ed aluminum alloys in the current studies were introduced. Control methods for defects in SLM-ed aluminum alloy from the perspectives of process optimization and microalloying were reported. And, the development of SLM-ed aluminum alloy was prospected.