In　order　to　achieve　active　health　monitoring　of　seven-wire　steel　strands,　single　magnetostrictive　transducer　with　two-layer　coil　is　developed　and　applied　for　the　excitation　and　reception　of　ultrasonic　longitudinal　guided　waves　simultaneously.　The　transducer　can　be　conveniently　fixed　at　any　single　one　position　on　the　helical　surface　of　these　structures.　The　inner　and　outer　layers　of　its　coil　are　used　for　excitation　and　reception　respectively　with　the　help　of　same　axisymmetric　permanent　magnets.　Experimental　results　show　that　chosen　ultrasonic　longitudinal　guided　wave　mode,　L(0,1)　at　140kHz,　can　be　excited　and　received　with　high　signal-to-noise　ratio　in　steel　strands　by　using　the　developed　magnetostrictive　transducer.　Furthermore,　to　identify　the　performance　of　the　transducer,　the　detection　of　an　artificial　defect　is　also　conducted.