This　article　adopts　a　method　of　measuring　the　hysteresis　loop　of　oriented　silicon　steel　sheet　under　the　excitation　of　pulse　width　modulation　(PWM)　signal.　A　measurement　platform　was　built　on　the　basis　of　the　traditional　Epstein　frame　method.　According　to　international　standards,　the　length　of　the　equivalent　magnetic　circuit　of　the　Epstein　frame　was　calculated,　and　the　harmonic　control　method　was　used　to　achieve　the　measurement　of　the　hysteresis　loop　of　the　oriented　silicon　steel　sheet　under　PWM　excitation.　Starting　from　the　traditional　sinusoidal　excitation,　this　paper　measures　the　variation　of　the　hysteresis　loop　of　the　silicon　steel　sheet　under　different　frequency　excitation.　On　this　basis,　the　waveform　control　and　PWM　signal　output　programming　were　carried　out　through　the　host　computer,　and　the　influence　of　high-order　harmonics　of　different　frequencies　on　the　magnetic　properties　of　the　oriented　silicon　steel　sheet　under　PWM　excitation　was　compared.　Provide　theoretical　basis　for　the　design　and　research　of　transformer　laminated　core.　©　2022,　The　Author(s),　under　exclusive　license　to　Springer　Nature　Singapore　Pte　Ltd.