In　traditional　cross-coupled　welding,　the　main　arc　swings　with　the　polarity　changes　of　the　bypass　arc,　leading　to　uneven　heat　distribution　and　compromising　the　decoupling　of　heat　and　mass　transfer.　To　address　this　issue,　a　new　cross-coupled　welding　method　based　on　high-frequency　bypass　arc　was　developed.　When　the　bypass　arc　operates　at　a　high　frequency　of　over　20　kHz,　the　main　arc　does　not　significantly　swing　with　the　polarity　shifts.　Instead,　it　vibrates　at　a　high　frequency　with　a　small　amplitude.　To　verify　whether　this　vibration　behavior　influences　the　molten　pool　flow　and　promotes　grain　refinement,　a　series　of　experiments　were　designed　and　conducted.　The　results　showed　that,　under　identical　conditions,　the　weld　width　produced　by　cross-coupled　welding　with　a　50　Hz　bypass　arc　is　greater　than　that　of　tungsten　inert　gas　welding　(TIG)　welding.　However,　under　highfrequency　bypass　arc　conditions,　the　weld　width　is　similar　to　that　of　TIG　welding,　indicating　a　more　effective　decoupling　of　heat　and　mass　transfer　in　this　method.　Moreover,　compared　to　TIG　welding　and　low-frequency　cross-coupled　arc　welding,　the　high-frequency　bypass　cross-coupled　method　refines　the　weld　zone　grains,　enhances　material　toughness,　and　improves　the　tensile　properties　of　the　weld.