Abstract: The forming process of selective laser melting is a coupling process involving multiple physical phenomena.The use of numerical simulation can effectively study the multiple physical phenomena in the forming process, explore the formation mechanism of defects and optimize the setting of process parameters. The present numerical simulation of laser selective melting in powder scale in China and foreign countries was reviewed, the key models of numerical simulation were introduced, the numerical simulation on the defects of laser selective melting in powder scale was analyzed, and the development direction and trend of numerical simulation of selective laser melting in powder scale were summarized and prospected.