Despite　of　the　promising　advantages　of　adopting　laser　powder　bed　fusion　(LPBF)　in　forming　of　Ti/Al　dissimilar　material　structure,　the　interfacial　property　has　been　one　of　the　most　critical　challenges　that　hinder　the　development　of　this　technology　for　further　application　in　engineering　fields.　A　fundamental　understanding　of　the　process-interfacial　property　relationships　is　crucial　for　process　optimization　and　performance　control　of　LPBFformed　dissimilar　material　parts.　Different　from　the　majority　literature　that　focuses　on　the　formation　of　pores　and　brittle　microstructures　at　the　interface　zone,　this　work　uniquely　explores　the　thermal　features　and　interfacial　stresses　(those　are　regarded　as　the　main　reasons　of　process　failures　and　fractures)　in　LPBF　forming　dissimilar　material　parts　and　the　influence　of　forming　height　on　the　residual　stress　distributions.　A　coupled　thermomechanical　model　using　the　finite　element　method　was　proposed　to　simulate　the　residual　stress　distributions　at　the　interfacial　zone　for　several　designed　part　parameters.　A　combined　experimental　and　numerical　study　was　conducted　to　record　the　interfacial　stress　field　of　different　forming　heights　to　reveal　the　mechanisms　of　stress　evolution　with　heat　accumulation.　The　numerical　results　show　that　the　interfacial　stress　increased　by　at　least　26　%　as　the　forming　height　of　AlSi10Mg　doubled,　while　it　decreased　to　50　%　with　stress　relieving　treatment　in　Ti6Al4V.　The　presence　of　initial　stress　and　heat　accumulation　both　lead　to　uneven　deformation　at　the　interface　zone,　thus　resulting　in　larger　residual　stresses.