Abstract: The laser energy density directly determines the melting state of the powder in the process of metal addictive material manufacture, and finally the microstructure and mechanical properties of the parts is affected. In order to reveal the shaping behavior of different laser energy density in the process of metal fabrication, taking 316L stainless steel laser selective melting molding as research object, the microstructure and mechanical properties of the parts made with different process parameters were analyzed. The influences of laser power parameters on the properties of the material was discussed. The results show that laser power has a relatively large effect on the melting state of powder, which furtherly affects the performance of the molded parts. In the SLM shaping manufacturing process, the hardness of the sample is the best when the laser energy density is 87 J/mm³.