The　additive　manufacturing　(AM)　3D　printing　technique　is　the　most　feasible,　advanced　technology　for　metal　parts　that　have　attracted　great　attention　in　the　manufacturing　industry.　AM　of　titanium　alloys　by　selective　laser　melting　(SLM)　is　one　of　the　most　recent　research　developments　in　this　field　because　of　its　benefits　and　wide　applicability　in　manufacturing　sectors.　SLM　is　an　efficient,　convenient　AM　technology　that　can　quickly　form　complex　structures.　A　well-known　titanium　alloy　named　Ti6Al4V,　manufactured　by　SLM,　has　several　practical　applications　in　engineering　technology,　including　cars,　space　shuttles,　and　aeronautics.　This　paper　demonstrates　the　density,　sectional　morphology,　microstructure,　and　mechanical　properties　before　and　after　heat　treatment　of　Ti6Al4V　alloy　sample　due　to　laser　power,　exposure　time,　and　line　spacing.　A　selective　laser　melting　technology　was　used　to　fabricate　the　Ti6Al4V　samples.　The　results　show　that　the　sample　defects　decreased　with　the　increase　in　laser　power.　Moreover,　when　the　laser　power　was　400　W　combined　with　an　exposure　time　of　30　mu　s,　the　sample＇s　tensile　strength　reached　1203　MPa,　almost　300MPa　greater　than　that　of　ordinary　forged　Ti6Al4V　titanium　alloy　after　annealing.　The　continuous　variation　in　the　line　spacing　within　a　certain　limit　(50-65　mu　m)　could　increase　the　relative　density　up　to　99.59%,　which　is　much　better　than　previously　reported　results.　The　tensile　fracture　of　the　sample　presents　a　brittle　crack.