In this study, the single-factor experiment was used to detect the roughness, observe the three-dimensional surface morphology, SEM morphology and density of GH3625 specimen with different selective laser melting（SLM) forming process parameters. The results show that within the experimental range, the upper surface roughness initially decreases and then increases with increasing laser power, scanning speed, scanning spacing, and scanning layers. Increased exposure times enhance cross-fusion between fused regions, slightly raising the surface roughness. Remelting, facilitated by higher scanning times, promotes the convergence of convex and concave surfaces, yet excessive remelting leads to repeated surface heating and elevated roughness. Optimum conditions of 168 W laser power, 600 mm/s scanning speed, 0.09 mm scanning distance, 2 scanning layers, and 2 exposure times yield a minimum upper surface roughness of 2.11 μm for GH3625 alloy, accompanied by a columnar and hexagon-like cellular microstructure and a final product density of 98.6%.