A　high　sensitivity　fiber-optic　acceleration　sensor　based　on　a　Fabry-Perot　Interferometer　(FPI)　formed　by　an　aluminum　alloy　elastic　mass-block　structure　is　proposed　for　measuring　acceleration　signals　in　a　vibrating　environment.　The　sensing　structure　mainly　consists　of　a　single-mode　optical　fiber　collimated　reflector　1,　reflector　2,　and　an　elastic　mass-block　structure,　where　the　optical　fiber　collimated　reflector　1　and　the　reflector　2　located　on　the　upper　surface　of　the　elastic　mass　block　form　an　F-P　interferometric　cavity.　According　to　the　F-P　interferometric　sensing　principle,　the　reflectivity　of　the　two　end　faces　and　the　cavity　length　parameters　are　simulated　and　optimized　to　produce　an　acceleration　sensor　with　a　high　finesse　reflectance　spectrum　(extremely　narrow　spectral　trough).　The　mass　block　dimensions　of　the　sensing　structure　were　simulated　and　optimized　and　performance　was　analyzed　using　finite　element　software,　and　the　sensor　was　fabricated　according　to　the　analysis　results,　and　the　amplitude-frequency　response,　sensitivity　characteristics,　and　lateral　anti-interference　capability　of　the　sensor　were　investigated　experimentally.　The　experimental　results　show　that　the　sensor　has　an　intrinsic　frequency　of　2100　Hz,　a　sensitivity　of　4.91　nm/g　at　1300　Hz,　a　resolution　of　0.204　mg,　and　a　transverse　immunity　of　less　than　5%　within　the　operating　bandwidth　of　0-1300　Hz.　The　sensor　proposed　in　this　article　is　characterized　by　high　sensitivity,　a　large　operating　bandwidth　range,　and　low　lateral　interference,　making　it　suitable　for　monitoring　medium-　and　high-frequency　vibration　signals　in　aerospace　and　other　equipment　structures.