Ceramic　materials　of　thermal　barrier　coatings　(TBCs)　inevitably　undergo　sintering　during　long-term　service,　which　can　deteriorate　the　performance　at　high　temperatures.　Sintering　behavior　is　commonly　a　key　index　for　evaluating　the　application　potential　of　TBCs.　Here,　we　conducted　the　thermal　exposure　experiments　on　the　novel　NdYbZr2O7　coating　at　1300　°C.　Results　show　that　multipoint　connection　is　the　dominant　sintering　mechanism.　Based　on　the　porosity　evolution,　the　whole　sintering　process　is　divided　into　two　stages:　1)　stage　I　characterized　by　the　healing　of　most　equal-width　intrasplat　cracks　and　narrow　tip　of　wedge-like　intersplat　cracks,　and　2)　stage　II　characterized　by　the　healing　of　residual　wide　part　of　intersplat　cracks.　As　the　thermal　exposure　duration　increases,　thermal　conductivity　of　coating　at　800　°C　increases　from　~0.72　W⋅m−1⋅K−1　to　~1.19　W⋅m−1⋅K−1.　The　linear　correlation　between　the　porosity　and　thermal　conductivity　indicates　that　porosity　is　the　critical　factor　controlling　the　thermal　conductivity　of　the　coating.　In　comparison　with　other　coatings　such　as　YSZ　and　SrAl12O19　reported　in　previous　literature,　NdYbZr2O7　coating　exhibits　better　thermal　insulation　and　higher　sintering　resistance.　In　addition,　Young＇s　modulus　of　coating　first　rapidly　increases　and　then　slowly　with　time,　closely　associated　with　the　evolution　of　porosity.　©　2023