In　this　paper,　a　pressure　sensor　based　on　high-birefringence　fiber　loop　mirror　(HiBi-FLM)　is　proposed　and　demonstrated.　The　high-birefringence　fiber　is　pasted　to　an　inflated,　elastic,　ring　shaped　rubber　gasbag　and　served　as　a　sensitive　probe.　When　outside　pressure　changes,　the　volume　of　the　gas　in　the　ring　rubber　gasbag　changes　and　it　makes　the　strength　of　the　high-birefringence　fiber　variety.　The　relationship　between　shift　of　the　resonant　wavelength　(peak　wavelength)　and　pressure　is　discussed　and　experimentally　researched.　Experimental　results　show　that　the　sensitivity　is　1.63x10(-3)　nm/Pa.　This　sensor　has　many　advantages　such　as　high　sensitivity,　polarization　independent,　easy　manufacture,　low　cost.