Recently,　fluoronitrile　C4F7N　is　regarded　as　a　promising　alternative　gas　for　SF6,　and　its　global　warming　potential　(GWP)　is　extremely　high.　C4F7N　has　good　insulation　properties　and　a　relatively　low　GWP,　so　it　can　be　used　as　an　insulation　medium　for　gas-insulated　switchgears.　Some　studies　have　been　conducted　on　the　decomposition　pathway　of　C4F7N　gas　that　may　produce　possible　neutral　molecules　and　free　radicals,　which　helps　understand　the　thermal　decomposition　of　C4F7N.　However,　anions　and　cations　will　be　produced　under　discharge　conditions.　In　these　cases,　the　decomposition　pathway　of　C4F7N　will　be　different.　In　this　paper,　the　ionization　decomposition　pathway　and　the　attachment　decomposition　pathway　of　C4F7N　were　first　calculated,　while　the　recombination　processes　of　the　cations　and　anions　were　also　considered.　The　results　can　reveal　the　decomposition　mechanism　of　C4F7N　and　the　recombination　mechanism　of　the　stable　products　under　discharge　conditions.　The　energy　changes　of　all　the　reactions　were　calculated,　which　reveals　the　difficulty　of　chemical　reactions.　To　better　investigate　the　formation　mechanism　of　stable　products,　the　partial　discharge　experiment　was　also　carried　out,　and　the　decomposition　products　of　C4F7N　mixed　gas　were　detected.　Finally,　the　ionization　energy　and　electron　affinity　energy　of　the　stable　products　were　also　calculated,　which　can　determine　the　difference　in　the　total　electronic　energy　between　the　neutral　molecule　and　the　ion.　The　results　provide　an　important　reference　for　studying　the　decomposition　characteristics　of　C4F7N　gas　under　discharge　conditions　from　the　theoretical　aspect.　©　2020　Author(s).