The selective laser melting (SLM) is a metal additive manufacturing (AM) technique in which a high-energy laser beam is used to melt the metal alloy powder on the designed two-dimensional cross-sections and solid parts are printed layer by layer from bottom to top. It has the advantages of high dimensional accuracy, good surface quality, high density and little material waste, and has been developed into one of the key AM technologies in the metal part forming field. The principle and research status of the SLM technology are introduced, and its applications in aerospace, medicine, automobile, mold and other aspects are summarized. In addition, its future development trend is prospected.