Rare　earth-doped　upconversion　nanomaterials　have　wide　application　prospects　in　photothermal　sensing，biomedicine　and　so　on，but　it　has　poor　thermal　conductivity，low　temperature　measurement　sensitivity　and　upconver⁃　sion　luminescence（UCL）intensity.　It’s　an　effective　way　to　improve　their　UCL　intensity　and　photothermal　perfor⁃　mance　by　assembling　composite　films　which　contain　single-walled　carbon　nanotubes（SWCNT），noble　metal　and　pho⁃　tonic　crystals（PCs）.　In　this　work，NaGdF4∶Er3+/Yb3+/Al3+　nanocrystalls（UCNPs）were　synthesized　by　the　solvother⁃　mal　method.　The　photothermal　performance　of　upconversion　layer（UC），SWCNT/UC，Ag/SWCNT/UC　and　PCs/Ag/　SWCNT/UC　were　compared，and　the　effects　of　different　film　layers　on　the　photothermal　performance　of　UCNPs　were　studied.　The　results　indicate　that　PCs/Ag/SWCNT/UC　has　the　best　performance，and　compared　with　the　UC　film，the　enhancement　factors　of　red　and　green　emission　intensities　are　3.　48　and　4.　24　times，respectively.　Its　photothermal　conversion　efficiency　is　33.　79%，which　is　1.　49　times　of　UC’s.　The　absolute　sensitivity（SA）of　the　optical　tempera⁃　ture　measurement　is　obtained　as　3.　14×10−3　K−1　at　353　K　and　the　relative　sensitivity（SR）is　obtained　as　1.　87×10−2　K−1　at　273　K.　The　work　provides　an　effective　way　to　improve　the　performance　of　the　photothermal　sensor.　©　2025　Editorial　Office　of　Chinese　Optics.　All　rights　reserved.