In　this　paper,　the　influence　of　air　arc-iron　wall　interactions　to　the　arc　volt-ampere　characteristics　is　studied　experimentally.　Under　the　experimental　conditions,　when　the　current　is　less　than　220　A,　arc-iron　wall　contacting　has　no　significant　effect　on　the　volt-ampere　characteristics　of　the　arc;　and　when　the　current　is　greater　than　220　A,　the　arc-iron　wall　contacting　obviously　increase　the　arc　voltage.　According　to　further　analysis,　when　the　current　is　greater　than　220A,　the　iron　vapor　generated　by　the　ablation　of　the　iron　wall　changes　the　properties　of　the　arc　plasma,　and　the　strong　radiation　of　the　air-Fe　arc　plasma　decreases　the　arc　temperature　which　increases　the　arc　voltage;　when　the　current　is　low,　the　amount　of　iron　ablation　is　small　and　it　has　few　effect　on　the　volt-ampere　characteristics　of　the　arc.　©　2019　by　International　Academic　Publishers　Ltd.