The　breaking　arc　of　intelligent　AC　contactor　has　an　important　effect　on　the　performance　and　electrical　life　of　contactor.　In　this　paper,　based　on　the　magneto　hydrodynamic　theory　(MHD)　and　the　dynamic　layering　mesh　technology,　the　mathematical　model　of　air　arc　in　the　breaking　process　of　intelligent　AC　contactor　is　established　and　the　arc　motion　in　arc　extinguishing　chamber　and　the　metal　plates　cutting　arc　process　are　simulated　and　the　validity　of　simulation　model　is　verified　by　experiment.　On　this　basis,　the　arcing　characteristics　of　the　zero-front-breaking　arc　under　AC4　condition　is　studied.　The　arc　extinguishing　performance,　arc　motion,　arc　root　transfer　and　the　arc　extinguishing　chamber　flow　field　of　four　different　metal　plates　and　magnetic　field　matching　schemes　are　investigated.　The　research　shows　that　the　plates　have　a　blocking　effect　on　arc　motion,　and　the　greater　the　thickness　of　plates,　the　more　difficult　the　arc　cutting　is.　Dense　plates　arrangement　has　great　hindrance　to　arc　flow.　For　the　zero-front-breaking　arc,　the　arc　extinguishing　ability　is　hard　to　be　improved　by　increasing　the　plate　number.　For　the　zero-front-breaking　arc,　the　arc　extinguishing　performance　can　be　effectively　improved　by　appropriately　reducing　the　thickness　of　the　plates　and　applying　external　magnetic　field.　©　2021　IEEE.