In　order　to　theoretically　explore　the　interfacial　bonding　properties　between　the　main　phase　(gamma)　and　the　second　precipitated　phase　(gamma＇)　in　K418　superalloy　formed　by　direct　laser　deposition.　First-principles　calculation　is　utilized　to　study　the　adhesion　work,　interfacial　energy,　electronic　structure,　bonding　properties,　and　tensile　properties　between　gamma　phase　(Ni　(001))　and　gamma＇　phase　(Ni3Al　(001)).　The　results　show　that　the　interface　energy　of　the　NiAl-center　(0.35-1.19　J　m(-2))　is　the　smallest　and　therefore　it　is　with　the　highest　interface　bonding　strength.　The　electronic　analysis　suggests　that　strong　Ni-Al　covalent　and　ionic　bonds　as　well　as　Ni-Ni　metal　bonds　at　the　interface　of　the　NiAl-center　model　are　formed　with　the　appearance　of　obvious　orbital　hybridization.　The　yield　strength　of　the　NiAl-top　model　reaches　up　to　19.38　GPa　under　the　uniaxial　tensile　test,　which　is　further　increased　when　doped　with　those　atoms　of　Re,　Ta,　and　W,　up　to　20.38,　20.42,　and　20.93　GPa,　respectively.　A　fundamental　understanding　is　presented　here　for　the　design　of　superalloys.