Recently,　the　series　arc　fault　detection　uses　the　main　line　current　as　decision　object,　which　is　easy　to　be　affected　by　the　singularity　of　normal　working　current　in　nonlinear　load　and　results　in　misjudgment.　And　the　arc　fault　characteristic　in　the　small　power　branch　is　easily　＇submerged＇　by　the　main　circuit　current,　which　leads　to　missed　judgment.　In　order　to　solve　this　problem,　according　to　the　electromagnetic　coupling　mechanism　of　high　frequency　arc　current,　a　detection　method　based　on　asymmetrical　distribution　of　L-N　lines　and　high-order　cumulant　identification　is　presented　in　this　paper.　Through　analyzing　the　coupling　signal　of　high　frequency　residual　flux　during　the　process　of　arcing　extinction　and　reignition,　the　kurtosis　of　the　coupling　signal　is　calculated　by　means　of　the　high-order　cumulant　statistical　tool.　In　this　paper,　the　arc　faults　in　different　conditions　such　as　combined　load　main　circuit　arc　fault　and　combined　load　branch　circuit　arc　fault　are　analyzed　and　judged,　and　the　unified　kurtosis　threshold　is　obtained.　The　results　show　that　the　method　can　be　effectively　used　to　detect　and　identify　series　arc　faults.　©　2019,　Science　Press.　All　right　reserved.