The　existing　voltage　arc-suppression　methods　have　the　problem　which　is　without　taking　account　of　the　arc-suppression　effect　of　distribution　networks　line　impedance　and　load　current.　It　would　lead　to　the　large　residual　current　at　the　fault　point　when　the　low　resistance　grounding　fault　occurs,　and　the　arc-suppression　effect　is　not　good.　This　paper　analyzes　the　three-sequence　networks　when　single-phase-to-ground　fault　occurs　in　three-phase　insulation　parameters　imbalance　of　distribution　networks.　The　influence　of　line　impedance　and　load　current　on　the　effect　of　existing　voltage　arc-suppression　method　is　studied,　and　propose　a　flexible　voltage　arc-suppression　method　considering　the　influence　of　line　impedance　and　load.　This　method　calculates　the　reference　value　of　zero-sequence　voltage　which　can　suppress　fault　point　voltage　to　zero　and　equivalent　impedance　value　of　fault　line　by　adjusting　the　zero　sequence　voltage　twice.　The　reference　value　of　zero　sequence　voltage　is　compared　with　the　three-phase　power　supply　voltage　in　distribution　networks,　and　the　ground　fault　phase　is　selected.　The　reference　value　of　zero-sequence　voltage　is　adjusted　according　to　the　equivalent　impedance　value　of　fault　line.　In　the　case　of　a　low-resistance　ground　fault,　the　voltage　and　current　of　the　fault　point　are　simultaneously　suppressed　to　zero,　reducing　the　damage　to　the　insulating　medium,　thereby　ensuring　the　reliable　extinguishment　of　the　fault　arc;　in　the　case　of　medium　and　high　resistance　ground　faults,　the　fault　point　voltage　is　suppressed　below　the　arc　reignition　voltage,　reducing　the　risk　of　damage　to　the　circuit　insulation　which　is　caused　by　long-term　overvoltage　operation　of　the　non-fault　phase.　The　simulation　verifies　that　the　method　can　achieve　good　arc　suppression　effect　for　single-phase　grounding　fault　under　any　fault　point　and　transition　resistance,　and　the　accuracy　of　phase　selection　is　high.　©　2022,　Power　System　Technology　Press.　All　right　reserved.