Usually,　the　broadband　light　source　(BBS)　is　used　in　more　point　measurement　by　means　of　fiber　Bragg　grating　(FBG)　sensors.　When　the　points　become　more　and　more,　especially　the　technology　of　time　division　multiplex　is　adopted　to　increase　large　number　of　measured　points,　the　BBS　dos　not　supply　enough　light　energy.　In　this　paper,　a　two-function　light　source　is　recommended.　It　can　both　amplify　the　light　power　and　demodulate　the　wavelength　signal.　Its　output　power　is　1000　times　as　high　as　BBS　and　it　can　demodulate　the　signal　by　scanning　wavelength　in　30　nm　of　bandwidth　range　in　the　situation　of　1550　nm　central　wavelength.　This　kind　of　light　source　effectively　solves　the　problem　of　light　energy　supply　in　more-point　measurement　of　FBG　and　simplifies　the　structure　of　sensing　measurement.