In　order　to　achieve　active　health　monitoring　of　steel　strands,　magnetostrictive　transducers　fixed　on　the　surface　of　the　structures　are　applied　for　the　excitation　and　the　reception　of　high-order　ultrasonic　longitudinal　guided　wave　modes　and　proper　parameters　are　optimized　for　the　identification　and　evaluation　of　the　defects.　The　sinusoidal　tone　burst　modulated　by　a　Hanning　window　is　used　for　an　exciting　high-order　ultrasonic　longitudinal　guided　wave　mode　L(0,　2)　at　0.86　MHz　in　seven-wire　steel　strands　to　detect　artificial　defects　machined　in　the　helical　and　center　wires　in　two　pieces　of　steel　strands　separately.　The　sensitivity　of　L(0,　2)　mode　to　defect　detection　in　different　wires　of　steel　strands　is　analyzed　experimentally,　and　furthermore　the　effects　of　the　defect　depth　and　the　cycles　of　excitation　signals　on　the　amplitudes　of　received　guided　wave　signals　are　researched.　Experimental　results　show　that　the　L(0,　2)　mode　at　0.86　MHz　can　be　used　for　the　defect　detection　in　the　steel　strand　with　the　help　of　magnetostrictive　transducers　while　the　mode　is　more　sensitive　to　the　defects　in　helical　wires　than　in　central　wires　of　steel　strands,　and　furthermore　the　defect　characterization　can　be　achieved　based　on　the　amplitudes　of　received　echoes.　Simultaneously,　it　is　important　for　the　defect　detection　in　steel　strands　to　optimize　the　cycle　number　of　the　excitation　signal　by　using　high-order　ultrasonic　longitudinal　guided　waves.