We　report　a　subnanoscale-displacement-resolution　optical　coherence　vibration　tomography　(SOCVT)　system　for　real-time　calibration　of　piezoelectric　actuators.　The　calibrations　of　the　actuators　at　nanoscale　or　microscale　displacement　ranges　were　performed　by　varying　the　input　voltage　over　the　entire　range　in　the　ascending　and　descending　directions.　The　computational　and　experimental　results　demonstrated　that　the　developed　SOCVT　could　be　used　to　characterize　the　dynamic　hysteretic　behavior,　nonlinear　effect,　and　impulsive　behavior　of　piezoelectric　actuators.　The　SOCVT　technique　is　non-contact　and　non-invasive　in　nature,　making　it　ideal　for　real-time　and　in　situ　ultra-precision　calibration　of　piezoelectric　actuators,　which　are　widely　used　in　active　vibration　control　and　nanopositioning.　(C)　2015　Elsevier　B.V.　All　rights　reserved.