Aiming　at　the　problem　of　the　direction　identification　and　quantitative　detection　of　cracks　in　metal　plate,　a　compound　imaging　method　for　plate　structure　is　developed　using　array　of　Lamb　waves.　From　the　total　matrix　data　of　single　mode　Lamb　waves　acquired　with　ultrasonic　array,　the　amplitude　and　sign　information　is　extracted,　which　are　used　for　total　focus　imaging　and　sign　coherence　imaging;　and　the　sign　coherence　imaging　is　used　to　perform　the　weighted　processing　for　the　full　focus　imaging.　The　total　array　is　divided　into　sub-arrays,　the　feature　vector　of　each　sub-array　is　calculated,　and　all　of　them　are　superimposed　with　weight　to　get　the　vector　total　focus　imaging;　Using　the　intensity　information　on　the　weighted　total　focus　imaging　and　the　direction　information　of　the　vector　total　focus　imaging,　the　compound　imaging　is　obtained,　from　which　the　orientation　and　dimension　information　of　the　crack　is　extracted.　The　experiment　results　demonstrate　that　the　proposed　compound　imaging　method　using　array　of　Lamb　waves　can　achieve　the　orientation　characteristic　identification　of　multiple　cracks　in　plate　nicely,　and　the　angle　measurement　errors　is　within　20%.　The　research　provides　a　useful　exploration　for　the　crack　defect　identification　and　quantitative　detection　of　metal　plate.　©　2016,　Science　Press.　All　right　reserved.