An　all-fiber　Fabry-Perot　interferometric　sensor　is　demonstrated　both　theoretically　and　experimentally.　The　proposed　structure　is　designed　and　fabricated　by　chemical　etching　combined　with　arc　discharge　welding　and　tapering.　The　single-mode　fiber　(SMF-28)　with　one　end　face　flattened　is　inserted　vertically　into　the　hydrofluoric　acid,　then　welded　with　another　SMF-28　by　arc　discharge,　to　form　a　bubble　by　welding　and　tapering,　which　exhibits　a　three-beam　interference　phenomenon.　High-temperature　sensitivity　of　12.88　pm/degrees　C　is　obtained　at　the　large　temperature　range　from　50　to　300　degrees　C,　with　excellent　linearity　of　0.9956.　The　Fabry-Perot　Interferometer,　with　low　processing　cost　and　high　performance,　can　provide　a　useful　application　in　temperature　sensing　prospects.