Nowadays,　it　is　difficult　to　accurately　measure　the　core　losses　of　magnetic　components　of　power　converter　under　high-frequency　excitation.　Based　on　the　DC　power　method,　this　paper　proposes　the　measuring　system　of　core　losses　at　l0MHz　using　a　new　wide　bandgap　semiconductor　device　GaN.　The　switching　process　of　the　DC/AC　inverter　circuit　is　analyzed　in　detail,　and　the　loss　model　of　the　DC/AC　inverter　circuit　is　established.　The　measuring　accuracy　is　verified　with　the　air-core　inductor,　whose　loss　can　be　accurately　measured,　and　the　maximum　relative　error　is　9.1%.　Finally,　the　core　losses　of　magnetic　components　under　l0MHz　excitation　are　measured　based　on　the　built　measurement　system.　©　2022　IEEE.