A　study　on　2219　aluminum　alloy　welding　using　high　frequency　energy　coupling　pulsed　TIG　welding　process　are　carried　out.　It　shows　that　using　a　special　AC　with　the　high-frequency　pulse　current　can　refine　the　microstructure　of　weld,　eliminate　pores　and　reduce　cracks　and　other　defects　effectively,　and　also　can　improve　the　properties　of　the　aluminum　alloy　joint　significantly.　The　properties　of　single-layer　joint　and　double-layer　joint　were　investigated　and　compared　by　means　of　quantitative　analysis　of　grain　size.　The　paper　proposed　a　way　to　reach　＇controllable　joint　property＇　by　thermal　cycles　controlling,　which　makes　the　joint　microstructure　more　homogeneous.　It　is　a　new　way　to　improve　the　comprehensive　mechanical　properties　of　joint　and　therefore　has　applicability　in　engineering.　©,　2015,　Harbin　Institute　of　Technology.　All　right　reserved.