In this paper, the used powder of 316L stainless steel with low cost was selected for selective laser melting （SLM）, and process parameter optimization and post-heat treatment were performed to improve the properties of the products. To be specific, after multiple groups of samples were prepared under different process parameters through the used powder with an average particle size of 27.6 μm, their microstructures were observed and their mechanical properties were tested. Then, some samples with good forming properties were adopted to study the effect of the heat treatment process with different cooling modes on the mechanical properties, corrosion resistance, and phase composition. The results show that when the laser energy density was 54 J/mm 3, the forming properties （hardness, tensile strength, elongation, etc.） of the samples were optimal, and the forming properties of the samples were closely related to the laser power and scanning speed in the case of constant laser energy density. After heat treatment, the hardness and tensile strength of the samples decreased, and the elongation and corrosion resistance improved. Besides, the austenite structure was not transformed, and only the grain size became larger. In conclusion, when the used powder of 316L stainless steel was employed for SLM, selecting reasonable forming parameters and heat treatment method can achieve good mechanical performance of the products.