An　frequency-domain　optical　coherence　vibration　tomography　(AE-OCVT)　system　based　on　acoustic　excitation　and　optical　coherence　tomography　is　proposed.　Its　applications　in　the　non-contact　structural　vibration　detection　and　modal　analysis　of　microbeams　are　also　studied.　The　AE-OCVT　system　utilizes　the　acoustic　signal　with　different　frequency　and　amplitude　to　excite　the　microbeams.　Then,　the　vibration　of　the　microbeam　is　measured.　In　this　way,　the　non-contact　and　nondestructive　vibration　detection　to　the　microbeam　structure　by　the　developed　AE-OCVT　system　can　be　carried　out.　It　is　better　than　the　conventional　method　based　on　the　contact　detection.　To　address　the　problem,　the　periodic　signal　in　frequency　domain　is　broadened　due　to　the　nonlinearity　of　time　domain　spectral　interference　signals　and　the　energy　leakage　from　the　time　domain　signal　with　window　truncation　during　Fourier　transform　of　the　spectral　signal.　The　spectral　wavelength　calibration　algorithm　and　the　spectrum　correction　algorithm　are　utilized.　After　the　error　correction,　the　AE-OCVT　system　has　ultra-precision　displacement　detection　accuracy.　The　axial　resolution　can　reach　the　sub-nanometer　level.　This　work　will　be　helpful　for　vibration　detection　and　modal　analysis　of　microstructures,　which　is　of　great　significance　to　the　design　of　micro-electromechanical　systems　(MEMS).　©　2018,　Science　Press.　All　right　reserved.