The　vibration-based　structural　health　monitoring　(SHM)　has　been　widely　studied　in　the　damage　identification　field.　Due　to　the　damage,　the　physical　parameters　of　the　structure　would　be　changed,　which　may　affect　the　dynamic　response　of　the　structures,　such　as　natural　frequencies,　damping　ratio,　phase,　mode　shape,　etc.　And　the　parameter　changes　could　be　used　to　predict　and　estimate　the　damage　information.　At　present,　most　SHM　studies　focused　on　the　frequency　changing　of　composite　plate,　but　the　damping　as　a　more　sensitive　parameter　has　not　been　adequately　utilized.　In　this　paper,　the　multi-mode　vibration　detection　method　is　proposed,　which　combined　with　the　natural　frequencies　and　damping　of　the　composite　plate　to　identify　the　delamination　information.　Through　simulating　the　effect　of　damages　on　composite　plate　with　finite　element　software　COMSOL,　the　one-to-one　mapping　relationship　between　multiple　modes　natural　frequencies　and　the　size　and　in-plane　location　were　obtained,　and　the　mode　3rd　and　mode　5th　were　selected　to　predict　the　delamination.　In　the　experiment,　carbon　fibre　composite　plates　with　artificial　delamination　were　fabricated.　The　vibration　mode　signals　were　detected　by　piezoelectric　materials　and　analysed　by　FFT　and　Hilbert　transform　to　calculate　the　natural　frequencies　and　damping　ratios　of　composite　plates.　By　the　inverse　problem　method,　the　predicted　values　of　X-location　were　consistent　with　the　actual　location　of　delamination　in　experiment,　which　the　error　was　less　than　3%.　©　2019　International　Committee　on　Composite　Materials.　All　rights　reserved.