A　dual-mode　film　bulk　acoustic　resonator　(DM-FBAR)　temperature　sensor　modulated　by　different　phosphorous-doped　silica　insertion　layers　was　reported　in　this　paper.　The　relative　drift　of　the　second　and　third　resonance　peaks　of　FBAR　could　improve　the　temperature　sensitivity　through　the　dual-mode　beat　frequency　calculation　method.　The　temperature　sensitivity　can　be　regulated　by　different　the　PH3　doping　flow　in　the　SiO2　insertion　layer.　Among　the　fabricated　devices,　FBAR　with　a　SiO2　insertion　layer　doped　4　sccm　PH3　has　the　highest　temperature　sensitivity　of　64.8　kHz　degrees　C-1.　It　is　discovered　that　the　greater　the　Young＇s　modulus　of　the　insert　film　changes　with　temperature,　the　higher　the　temperature　sensitivity　of　DM-FBAR　device.　Therefore,　an　important　technical　means　to　improve　the　performance　of　DM-FBAR　devices　is　using　the　material　whose　Young＇s　modulus　is　more　sensitive　to　temperature　in　the　future.