In　welding　steel　with　aluminum,　the　intermetallic　compound　of　Fe　and　Al　will　appear,　which　will　decrease　the　tenacity,　increase　the　hardness,　and　lead　to　a　bad　joint　performance.　A　new　kind　of　low　energy　input　(LEI)　welding　technology　is　introduced　and　it　can　be　used　to　weld　steel　with　aluminum　by　using　4047　wire.　The　whole　welding　process　is　a　circulation　process　of　＇arcing-short　circuit＇,　in　which　the　heat　input　is　reduced　greatly.　By　using　this　technology,　brazing　is　located　on　the　steel　side　and　arc　fusion　welding　on　the　aluminum　side.　From　the　metallic　phase　and　scanning　electron　microscope,　a　continuous　and　compact　intermetallic　compound　layer　with　a　thickness　of　3~4　μm　can　be　observed,　which　forms　in　the　interface　region　of　the　welding　seam　metal　and　the　galvanized　sheet.　The　main　components　in　the　layer　are　Fe2Al5　and　FeAl3,　without　Zn.　Tensile　strength　tests　prove　that　the　joint　breaks　in　the　heat　affect　zone,　and　the　strength　is　higher　than　70%　that　of　the　aluminum　alloy　base　material.　So,　LEI　can　lead　to　a　good　performance　joint.