The　harmonic　transfer　characteristics　of　electromagnetic　current　transformer　is　complex,　and　the　transfer　error　varies　and　is　hard　to　estimate.　This　article　designs　the　experiment　of　hysteresis　loop　of　ferromagnetic　material,　and　analyzes　the　influence　of　the　hysteresis　loop　shape　on　the　transfer　error　of　current　transformer.　Aiming　at　the　difficulty　of　high　accurate　detection　of　harmonic　error,　a　high-precision　detection　system　of　current　transformer　harmonic　error　was　developed.　With　the　experiment,　the　influence　of　frequency,　load,　fundamental　current,　harmonic　phase　and　DC　component　on　the　harmonic　transfer　error　of　current　transformer　is　analyzed.　©　2017,　Science　Press.　All　right　reserved.