A　novel　long-period　fiber　grating　(LPFG)　with　a　four-layer　structure　is　proposed,　made　by　coating　double　layers　of　both　ZnO　and　Ag　onto　a　bare　LPFG.　Pulsed　laser　deposition　(PLD)　technology　can　effectively　control　the　flatness　and　nanoscale　thickness　of　ZnO　film,　which　is　conducive　to　achieving　full　energy　coupling　with　the　Ag　layer　and　the　grating.　Compared　with　SiO2,　ZnO　has　a　higher　thermal　expansion　coefficient　and　refractive　index,　which　ensures　that　coated　LPFG　has　a　higher　temperature　sensitivity.　As　the　fourth　layer　of　the　structure,　colloidal　silver　is　coated　onto　the　surface　of　the　ZnO　film　at　an　optimal　thickness　by　a　spin-coating　method.　The　higher　thermal　expansion　coefficient　of　the　Ag　film　and　a　plasma　resonance　effect　on　its　surface　cause　the　temperature　sensitivity　to　increase　again.　The　sensitivity　of　the　coated　Ag-ZnO-LPFG　structure　is　1.4　times　higher　than　that　of　the　bare　fiber.　The　temperature　sensitivity　is　increased　from　0.063　nm　degrees　C-1　to　0.088　nm　degrees　C-1,　while　retaining　good　linearity.　We　also　solve　the　problem　whereby　the　coating　disturbs　the　coupled-wavelength　transmittance,　and　by　doing　so,　we　increase　the　stability　of　the　coupled-wavelength　transmittance　and　enhance　measurement　accuracy.