Abstract: Selective laser melting forming was applied to 316L stainless steel powder. The effects of laser power, scanning speed and scanning interval on the relative density, tensile properties and micromorphology of formed samples were analyzed by the orthogonal method, and the optimal process parameters were obtained. The results show that the tensile strength, yield strength and relative density of the formed sample increased and then decreased with increasing laser power or scanning speed, and increased with increasing scanning interval. The elongation decreased and then increased with increasing laser power, increased with increasing scanning speed, and changed little with increasing scanning interval. The optimal process parameters obtained were as follows:laser power of 310 W, scanning speed of 960 mm·s^-1 and scanning interval of 0.13 mm. The relative density, tensile strength and yield strength of the formed sample with the optimal process parameters were the highest of 99.53%, 613 MPa and 320 MPa, respectively, and the elongation was 44.6%; the formed sample had a smooth surface and small pores; the tensile fracture showed small and uniform dimples and less balling phenomena.