Combined　with　the　modified　damage　imaging　algorithm　based　on　Reconstruction　Algorithm　for　the　Probabilistic　Inspection　of　Damage　(RAPID),　a　baseline-free　detection　method　of　the　Lamb　waves　based　on　time　reversal　method　is　developed　to　detect　the　delamination　in　the　composite　plate.　Through　the　analysis　of　the　focus　position　of　time　reversal　signal,　a　new　calculation　method　of　Damage　Index　(DI)　values　is　proposed.　The　modified　damage　imaging　algorithm　based　on　RAPID　is　integrated　with　two　image　fusion　methods:　full　summation　method　and　full　multiplication　method.　According　to　the　analysis　of　limitations　of　the　modified　damage　imaging　algorithm,　the　transducer　array　is　adopted,　and　the　problem　of　the　uneven　probability　distribution　caused　by　the　uneven　density　of　sensing　network　is　discussed.　Modified　methods　are　proposed　to　eliminate　the　influence　of　the　uneven　probability　distribution　and　improve　the　accuracy　and　reliability　of　the　detection　results.　The　parameter　significantly　affects　the　effective　detection　range　of　each　sensing　path　in　the　modified　damage　imaging　algorithm.　The　value　of　parameter　was　experimentally　determined　and　reasonably　applied　to　detect　the　delamination.　Based　on　the　calculation　of　the　DI　of　individual　sensing　path　and　the　imaging　results　of　delamination,　the　identification　and　localization　of　delamination　were　experimentally　achieved.　The　imaging　results　demonstrated　the　problem　of　the　uneven　probability　distribution　and　the　validity　of　modified　methods.　Copyright　(c)　2016　John　Wiley　&　Sons,　Ltd.