In　this　paper,　a　high-precision　accelerometer　based　on　single-level　diffraction　of　a　single　grating　is　optimized　and　improved.　The　sensor　consists　of　an　optical　system　displacement　measurement　system　using　grating　interferometry　and　a　mechanical　structural　part　made　of　silicon.　The　sensor　is　analyzed　by　finite　element　analysis　(FEA)　and　strictly　coupled　wave　analysis　methods.　The　optical　accelerometer　has　an　optical　sensitivity　of　2.21%/mu　m　over　the　entire　measurement　range,　and　total　sensitivity　of　system　is　424%/g　(note:　1　g　=　9.8　m/s(2))　with　and　a　cross　sensitivity　of　3.21%.　Furthermore,　the　first-order　resonant　frequency　is　35.995　Hz　and　the　linear　measurement　range　is　+/-　0.0177　g.　Compared　with　other　low-frequency　sensors,　a　high-performance　accelerometer　sensor　is　realized.　And　can　be　applied　to　high-tech　fields　such　as　inertial　navigation　and　guidance　system,　space　ocean　gravity　distribution　measurement,　and　artificial　intelligence.