Plasma　transport　during　continuous　extinction　processes　from　high-current　arcs　to　full　extinction　is　an　important　issue　in　the　study　of　vacuum　arcs.　However,　to　describe　this　transition,　the　traditional　methods,　magneto　hydrodynamics　or　particle-in-cell,　are　limited　by　either　accuracy　or　efficiency.　In　this　paper,　we　developed　a　fully　3D　hybrid　plasma　simulation　algorithm　to　study　the　extinction　process　of　multiple　cathode　spots　in　a　vacuum　environment.　Cathode　spots　are　modelled　as　independent　plasma　sources　rather　than　treating　the　whole　cathode　surface　as　an　indivisible　source.　For　a　better　balance　between　efficiency　and　accuracy,　ions　are　modelled　as　particles　and　electrons　are　treated　as　a　massless　fluid.　Using　this　model,　the　effects　of　cut-off　time　and　the　locations　of　cathode　spots　on　the　extinction　process　are　studied.　The　results　show　that　during　an　extinction　process,　the　total　number　of　ions　between　the　electrodes　gradually　decreases　and　the　mean　velocity　of　the　ions　gradually　increases.　When　the　current　approaches　zero,　two　regions　can　be　observed　in　the　gap:　the　separated　jet　region,　and　the　common　plasma　channel　region.　The　last　three　surviving　cathode　spots　have　significant　impacts　on　the　ion　distribution　at　current　zero,　whose　values　depend　on　the　distances　to　them.　The　closer　together　the　three　cathode　spots　are,　the　higher　the　value　that　the　local　ion　density　will　reach.　In　addition,　at　current　zero,　the　maximum　ion　density　appears　near　the　last　extinguished　cathode　spot.　©　2020　IOP　Publishing　Ltd.