Intelligent　AC　contactor　is　a　new-type　controllable　apparatus,　which　composed　by　a　microprocessors　controlled　intellectual　control　module　and　the　traditional　AC　contactor.　So　it　can　be　optimizing　control　in　all　process　of　closing,　closed　and　breaking.　By　changing　the　contact-structure　of　AC　contactor,　three-phase　contacts　have　different　opening　distances.　The　contactors　not　only　realize　no-are　or　little　arc　closing　and　breaking,　but　also　will　have　higher　electrical　endurance,　operating　frequency　and　better　performance　indexes.　This　paper　shows　its　control　principal,　analyzes　the　reason　why　the　zero-current-break　control　(ZCBC)　fails.　A　new　algorithm　-ant　colony　algorithm　(ACA)　is　used　for　the　optimize　design　in　electromagnetic　device　of　intelligent　AC　contactor.　The　magnetic　properties　and　the　controls　parameter　of　the　contactor　are　studied.　The　contactors　will　have　more　suitable　electromagnetic　device　and　action　characteristics.　The　operation　dependability　of　contactor　improves　greatly,　and　realizes　saving-material　(especially　silver)　and　saving-energy.