In　this　research,　to　solve　the　problem　of　the　ultrasonic　guided　wave　inspection　of　a　U-shaped　boom,　an　improved　periodic　permanent　magnet　electromagnetic　acoustic　transducer　(PPM　EMAT)　is　proposed　for　defect　detection　for　a　U-shaped　boom.　The　acoustic　field　distribution　range　of　a　traditional　PPM　EMAT　is　approximately　+/-　20　degrees,　and　the　energy　distribution　is　relatively　concentrated.　By　adjusting　the　tilt　angle　between　adjacent　magnets　and　coils　of　a　traditional　PPM　EMAT,　an　improved　PPM　EMAT　is　proposed.　The　acoustic　field　distribution　range　of　the　improved　PPM　EMAT　is　approximately　+/-　30　degrees,　and　the　energy　distribution　in　this　range　is　relatively　uniform.　The　simulation　and　experimental　results　show　that　the　improved　PPM　EMAT　has　superior　frequency　response　characteristics　and　acoustic　field　directivity,　which　is　suitable　for　detecting　large　and　complex　structures.　Furthermore,　based　on　the　traditional　PPM　EMAT　and　the　improved　PPM　EMAT　array,　combined　with　the　reconstruction　algorithm　for　the　probabilistic　inspection　of　damage　(RAPID),　the　damage　locations　of　the　double-hole　defects　of　a　U-shaped　boom　are　studied.　It　is　shown　that　the　imaging　results　for　defect　location　using　the　improved　PPM　EMATs　are　better　than　those　found　using　the　traditional　PPM　EMATs.