Theoretically,　the　cross　coupled　arc　(CCA)　welding　process　holds　the　potential　for　decoupling　heat　and　mass　transfer　during　welding,　allowing　for　independent　control.　However,　conventional　CCA　processes　typically　utilize　low-frequency　alternating　current　(AC)　as　input　heat　sources　for　the　bypass　arc,　which　can　lead　to　oscillation　of　the　main　arc　due　to　changes　in　polarity　of　the　bypass　arc.　This　arc　oscillation　can　result　in　uneven　heat　distribution　among　arcs,　consequently　affecting　the　decoupling　effect　on　heat　and　mass　transfer.　When　applied　in　additive　manufacturing,　it　may　cause　issues　such　as　uncontrollable　droplet　placement　and　reduced　molding　accuracy.　To　reduce　the　main　arc　oscillation,　this　study　presents　a　designed　and　developed　CCA　welding　heat　source　using　a　high-frequency　AC　square　wave　with　an　output　frequency　up　to　20　kHz　for　input　of　bypass　arc.　Through　analyses　and　experimental　verification,　it　has　been　demonstrated　that　increasing　the　variable　polarity　frequency　effectively　suppresses　the　main　arc　oscillation,　achieves　control　over　the　melting　rate　of　the　filled　welding　wire　within　the　CCA,　and　enables　decoupled　heat　transfer　between　the　workpieces＇　input　energy.　Furthermore,　after　suppressing　main　arc　oscillation,　it　operates　with　high-frequency　vibrations　at　small　amplitudes　expected　to　induce　stirring　effects　on　molten　pools,　promoting　dendrite　fragmentation　and　weld　grain　refinement,　which　has　important　potential　application　and　research　value.　©　2024　The　Society　of　Manufacturing　Engineers