Abstract: In order to improve the technological property of selective laser melting forming 316L stainless steel, the side surface properties and density of 316L stainless steel samples at different forming angles (40°, 50°, 60°, 70°, 80°, 90°) were studied. The results show that with the increase of the forming angle, the roughness of the side surface of the sample decreases, the residual stress on the side surface is tensile stress and gradually decreases, and the density is greater than 99%, and gradually increases; and the performance of the sample is optimal when the forming angle is 90°, at this time, the side surface roughness value R_a =5.0385 m, the residual stress value is 103.47 MPa, and the density value reaches the maximum of 99.91%.