Abstract: The forming quality of selective laser melting (SLM) is mainly related to scanning laser parameters and scanning path strategy.In order to reduce the displacement deviation, internal equivalent stress and the surface roughness of the formed surface, first of all, the stress distribution and geometric displacement of the parts were studied by the thermal strain simulation using ANSYS Additive software under the two conditions of horizontal alignment melting and overlapping melting of the upper and lower layers.The results show that the displacement and internal stress are reduced through the overlapping melting of the upper and lower layers.Then, on the basis of thermal strain simulation analysis, a scanning strategy of secondary overlap melting of the upper and lower layers in a small area was adopted and 316L stainless steel powder was used for small area sample forming experiments on SLM machine.The results show that the obtained forming quality can meet the requirement.