The　Dynamic　Magnetostriction　(DM)　measurement　method　as　a　nondestructive　testing　method　of　ferromagnetic　materials,　measures　the　DM　curve　using　electromagnetic　acoustic　transducer　(EMAT)　to　characterize　material　and　predict　the　mechanical　properties.　Lorentz　forces　and　magnetostriction　forces　contribute　mainly　to　the　ultrasonic　generation.　Only　the　range　of　low　field,　in　which　the　magnetostriction　force　mechanism　is　predominant　can　be　used　to　measure　the　DM　curve,　but　the　boundaries　of　this　range　are　uncertain.　The　improved　DM　measurement　method　based　on　shear　wave　Magnetostriction　EMAT　(M-EMAT)　is　proposed　and　the　theory　of　generation　of　shear　waves　is　derived.　For　the　M-EMAT,　only　magnetostriction　force　mechanism　contributed　to　the　generation　of　shear　waves.　A　theoretical　model　for　the　optimization　of　the　transducer　is　developed,　the　model　is　in　good　agreement　with　the　experimental　results.　The　microstructure　changes　caused　by　residual　strain　will　affect　the　magnetostriction　coefficient　and　the　DM　curve.　Therefore,　the　DM　curves　of　low　carbon　steel　specimens　with　different　levels　of　residual　strains　are　measured　by　the　optimized　transducer　to　characterize　the　residual　strain.　The　normalized　results　demonstrate　that　the　slope　of　the　DM　curve　obviously　changes　with　the　residual　strain.　This　leads　to　the　conclusion　that　the　DM　measurement　method　can　be　used　to　characterize　the　residual　strain　of　the　low　carbon　steels.