Abstract: Additive manufacturing technology is one of the advanced manufacturing technologies that is currently receiving much attention, and has been widely applied in industries such as aerospace, military, automotive, and medical. The additive manufacturing process is affected by the performance of metal powder materials, forming processes, and forming equipment, so additive manufacturing of metal formed parts may have quality risks such as porosity, lack of fusion, and cracks that affect density, leading to a decrease in the performance and quality of additive manufacturing metal formed parts and their inability to be used. This paper used 316L stainless steel as raw material and laser selective melting process to form 35 standard samples. Industrial CT was used to test and analyze their density, and the influence of forming process parameters on density was correlated and analyzed. The results indicated that industrial CT was an effective method for density detection in additive manufacturing of metal formed parts.