Thermal　insulation　performance　is　a　measurement　of　the　thermal　protection　offered　by　the　thermal　barrier　coatings　(TBCs)　to　the　substrate,　therefore,　it　is　essentially　important　to　compare　different　double　ceramic　layer　(DCL)　TBCs　on　the　premise　of　the　same　thermal　resistance.　In　this　study,　a　series　of　LZO/YSZ　DCL-TBCs,　with　the　equivalent　thermal　insulation　to　500　μm　thick　YSZ　TBCs,　were　prepared,　and　their　lifetimes　were　evaluated　by　thermal　gradient　cyclic　test　at　the　top　coat　surface　temperature　of　1300°C.　Result　show　that,　the　lifetime　of　DCL-TBCs　was　more　than　doubled　compared　to　500　μm　thick　YSZ　TBCs,　when　100pm　thick　YSZ　coating　was　substituted　by　LZO　coating.　In　addition,　the　lifetime　of　DCL-TBCs　decreased　with　the　increase　of　LZO　substitutional　ratio.　X-ray　diffraction　analysis　revealed　that　LZO　maintains　the　pyrochlore　structure　after　thermal　cyclic　test.　Microstructure　examination　demonstrated　that,　with　the　increase　of　LZO　substitutional　ratio,　the　delamination　position　transferred　from　near　top/bond　coating　interface　to　near　LZO/YSZ　interface　and　finally　to　the　inside　of　LZO　coating.　Therefore,　this　study　would　shed　light　to　further　coating　structure　optimization　towards　the　next　generation　advanced　DCL-TBCs.　©　Copyright　2017　by　DVS　Media　GmbH.　All　rights　reserved.