Laser　powder　bed　fusion　(LPBF)　process　is　a　promising　additive　manufacturing　technique　to　manufacture　multi-material　integrated　parts　with　complex　structures.　In　this　paper,　the　multi-material　structure　of　Ti6Al4V/AlSi10Mg　is　fabricated　by　LPBF,　the　interfacial　characterization,　interfacial　reaction　mechanism　and　mechanical　properties　of　Ti/Al　structure　are　investigated.　Results　show　that　continuous　and　excellent　metallurgical　bonding　between　Ti6Al4V　and　AlSi10Mg　is　obtained,　and　the　width　of　interface　zone　is　about　100　μm.　The　equiaxed　grains　of　aluminum　alloy　at　the　interface　show　random　crystallographic　orientation,　which　is　attributed　to　the　thermal　dynamics　in　the　melt　pool,　thermal　cycles　during　LPBF　process　and　lower　thermal　conductivity　of　titanium　alloy.　The　interfacial　reaction　layers　are　orderly　from　titanium　alloy　to　the　aluminum　alloy　consisting　of　Ti3Al,　TiAl　with　nanoparticles　Ti5Si3　and　rod-like　TiAl3.　The　segregated　Si　atoms　react　with　the　dissolution　of　Ti　atoms　in-situ　to　form　Ti5Si3,　meanwhile,　a　mass　of　Al　atoms　also　react　with　Ti　atoms　to　form　TiAl.　Namely,　the　TiAl　phase　forms　in　thin　layer　shape　embedded　with　nanoparticles　Ti5Si3　through　eutectic　reaction　near　the　fusion　line　at　the　interface.　At　the　wall　of　eutectic　production,　the　TiAl3　phase　nucleation　and　grow　opposite　to　the　heat　dissipation　direction　and　vertical　to　the　fusion　line.　Outside　the　fusion　line,　the　supersaturated　solid　α-Ti　transforms　to　Ti3Al　through　the　diffusion　of　Al　atoms　in　the　part　of　titanium　alloy.　During　the　interfacial　reaction,　in-situ　generated　nanoparticles　Ti5Si3　could　improve　the　joint　strength,　and　the　tensile　strength　of　Ti6Al4V/AlSi10Mg　specimens　reached　264.8　±　22.4　MPa.　The　tensile　specimens　exhibit　brittle　fracture　and　two　typical　fracture　morphologies　appear　on　the　fracture　surface.　©　2022