Lamb　waves　can　achieve　defect　detection　and　monitoring　with　large　scale　and　high　efficiency　in　plate-like　structures　because　of　its　advantages　including　long　propagation　ability　and　low　attenuation.　Thus,　Lamb　wave　technology　has　immense　application　potential　in　nondestructive　testing　and　structural　health　monitoring.　Aiming　at　consistently　exciting　single　Lamb　wave,　S0　mode,　in　circumferential　direction　and　improving　imaging　ability　for　the　wide　range　health　monitoring　of　plate-like　structure,　an　omni-directional　S0　mode　magnetostrictive　transducer　is　developed　on　basis　of　magnetostrictive　effect　and　it　consists　of　a　coil　on　PCB,　a　cylindrical　magnet　and　a　circular　nickel　patch.　The　experimental　results　firstly　verify　that　this　type　of　transducer　can　effectively　produce　the　pure　S0　mode　in　an　aluminum　plate.　Then,　the　frequency　response　characteristics　and　omni-directivity　of　this　developed　transducer　are　tested.　The　results　demonstrate　that　developed　transducer　has　a　center　frequency　of　365　kHz　and　high　omnidirectional　consistency.　Furthermore,　a　distributed　sparse　transducers　array　is　built　by　using　developed　omni-directional　S0　mode　magnetostrictive　transducers.　An　aluminum　plate　is　detected　in　pulse-echo　mode　by　using　this　transducer　array.　The　combination　of　discrete　arc　imaging　and　data　fusion　algorithm　is　used　to　deal　with　multiple　sets　of　data,　which　eliminates　the　dependence　upon　the　signals　in　health　condition　compared　with　the　conventional　sparse　transducers　array　imaging　algorithms.　The　location　and　imaging　of　the　defect　could　be　well　achieved　without　the　need　of　reference　signals　in　health　condition.　©　2015　Journal　of　Mechanical　Engineering.