Warping deformation often occurs during the process of selective laser melting (SLM) of parts, which is related to addition of part supports. Therefore, it is necessary to investigate the addition manner of part supports in the SLM process. The molding effects in the SLM of parts with different support structures are investigated and one found that, under the condition of same support parameters, the support sheet which is separated and non-inclined has better molding effects; the larger the height of support structure is, the stronger the warping deformation is. After the optimization of support structures, it is found that the separated and non-inclined support structure mixed with heat conduction columns can effectively reduce the warping deformation of parts. This study provides a reference basis for the molding of high precision parts by SLM.