Abstract: Selective laser melting（SLM） is one of the additive manufacturing processes for metal part, and it has many parameters and the forming process is immature. There are metallurgical defects such as pores, cracks, residual stress and strain in 316L SLM formed parts. From the aspect of SLM process of 316L stainless steel, the controllable parameters in the printing preparation stage, printing stage and post-processing stage were analyzed and summarized, and the effect laws of the above controllable parameters on the metallurgical defects and mechanical properties were emphatically introduced. The research direction in future was prospected.