The　distribution　of　each　phase　short-circuit　current　can　be　changed　by　the　variation　of　the　distributed　generation　capacity　when　the　single　phase　ground　fault　occurs　in　the　distribution　network.　But　it　cannot　change　the　characteristics　of　the　zero-sequence　current　in　the　head　of　each　line,　i.e.　the　sum　of　the　zero-sequence　currents　in　the　non-fault　lines　equals　the　head　line　zero-sequence　current　in　the　fault　line　but　they　have　the　inverse　direction　for　the　non-power　frequency　zero-sequence　currents.　This　feature　can　be　used　as　a　fault　line　selection　criterion.　This　paper　proposes　a　novel　method　using　Hilbert-Huang　transform　algorithm　to　extract　the　non-power　frequency　component　of　the　zero　sequence　current　in　each　line,　and　calculates　their　energy　weighting　coefficient.　Then　the　digital　notch　filter　is　used　to　extract　the　5th　harmonic　current　of　the　zero　sequence　current.　It　can　be　concluded　that:　(1)　the　fault　occurs　in　the　bus　if　the　direction　of　the　5th　harmonic　current　is　same;　and　(2)　when　one　line　has　the　largest　energy　weight　coefficient　and　its　direction　of　the　5th　harmonic　current　is　different　from　others,　the　fault　occurs　in　the　line.　Through　simulations,　the　proposed　method　is　proved　to　be　able　to　select　the　fault　line　accurately　and　reliably　in　the　difficult　cases,　i.e.　the　small　angle　fault,　the　high-impedance　ground　fault,　and　the　fault　in　the　end　of　line　and　etc.,　with　high　accuracy　and　reliability.　©,　2015,　The　editorial　office　of　Transaction　of　China　Electrotechnical　Society.　All　right　reserved.