Lamb　waves　defect　detection　technique　is　suitable　to　detect　long-range　defects　and　multi-defects　in　plates　because　of　its　attractive　properties　such　as　multi-modes,　low　attenuation,　and　multi-defect　sensitivity.　As　the　laser　beams　have　the　tiny　size　and　noncontact　property,　in　this　paper　a　full　non-contact　laserbased　Lamb　waves　phased　array　inspection　technique　was　proposed　for　defect　detection　in　an　aluminum　plate.　A　Q-switched　Nd:　YAG　pulse　laser　generating　Lamb　waves　and　a　continuous　laser　inspection　system　was　used　to　inspect　the　out-of-plane　displacements.　The　laser-generated　Lamb　waves　have　the　broadband　property　and　low　temporal　resolution　that　are　not　suitable　for　defects　detection　directly.　So　the　continuous　wavelet　transform　was　used　to　extract　narrowband　signals　from　laser-generated　Lamb　wave　and　a　linear　mapping　algorithm　was　adopted　to　compensate　for　the　dispersion　of　the　extracted　narrowband　signals.　Two　experiments　were　carried　out　to　verify　the　applicability　and　effectiveness　of　the　developed　full　non-contact　laser-based　Lamb　waves　phased　array　inspection　technique.　Two　compact　phased　array　imaging　algorithms,　the　total　focusing　method　and　the　sign　coherence　factor　algorithm,　were　adopted　to　image　the　defects　with　processed　signals.　The　experimental　results　accurately　located　the　positions　of　the　defects.