In　this　paper,　Ti6Al4V/AlSi10Mg　multi-material　specimens　were　fabricated　by　selective　laser　melting　(SLM).　The　influence　of　process　parameters　on　the　interfacial　crack　was　discussed　and　the　formation　mechanism　of　interfacial　crack　under　different　process　parameters　was　expounded　through　the　simulation　of　temperature　field.　The　microstructure,　element　distribution,　phase　composition　and　microhardness　of　the　Ti/Al　interface　were　investigated.　The　cooling　rate　and　temperature　gradient　increased　with　the　increase　of　laser　power　and　scanning　speed,　which　easily　led　to　the　interfacial　crack.　Using　chess　scanning　strategy　and　increasing　the　preheating　temperature　of　the　substrate　could　effectively　reduce　the　cooling　rate,　so　as　to　reduce　the　stress　and　avoid　the　interfacial　crack.　There　was　a　good　metallurgical　bonding　between　titanium　alloy　and　aluminum　alloy,　the　typical　molten　pool　morphology　could　be　seen　at　the　interface.　In　the　heat　affected　zone　near　the　interface,　the　grain　size　of　aluminum　alloy　became　coarsen,　because　the　lower　thermal　conductivity　of　titanium　alloy　and　heat　accumulation　in　the　process　of　forming　aluminum　alloy.　There　were　needle-like　intermetallic　compounds　(IMCs)　at　the　interface.　According　to　the　results　of　SEM　and　EDS,　the　thickness　of　IMCs　was　about　2-4　μm,　and　the　composition　of　IMCs　was　mainly　TiAl　and　TiAl3.　The　results　of　XRD　showed　that　there　were　not　only　Ti3Al,　TiAl,　TiAl3　IMCs　but　also　TiSi2　ceramic　phase　at　the　interface,　which　made　the　microhardness　of　the　interface　reached　as　high　as　679　HV.　©　2021　SPIE.