This　study　proposes　a　novel　bypass-coupled　variable-polarity　plasma　arc　additive　manufacturing　process.　This　process　enables　independent　control　of　the　main　current,　bypass　current,　and　their　polarities,　thereby　achieving　decoupled　control　of　thermal　input　to　the　deposited　layers　and　wire　melting.　Additionally,　the　variable　polarity　effectively　removes　the　oxide　film　on　the　surface　of　aluminum　alloys,　improving　defects　in　aluminum　alloy　additive　manufacturing.　The　research　results　indicate　that　the　bypass-coupled　variable-polarity　plasma　arc　additive　manufacturing　presents　different　metal　transfer　forms　compared　to　conventional　arc　additive　manufacturing　(MIG/TIG　arc　heat　sources).　The　droplet　transfer　behavior　manifests　in　various　forms　at　different　wire　heights,　including　droplet　transfer,　Intermittent　bridging　transfer,　and　complete　bridging　transfer.　Notably,　the　complete　bridging　transfer　results　in　short　metal　bridge,　which　weakens　the　influence　of　the　coupled　arc　magnetic　field　and　provides　a　wider　process　window　for　shaping.　A　detailed　analysis　of　the　effects　of　main　and　bypass　EN/EP　currents　on　the　formation　morphology　reveals　that　the　influence　of　the　main　EN　current　on　the　width　of　the　deposited　layer　is　twice　that　of　the　bypass　EN　current.　By　adjusting　the　main　EN　current,　the　remelting　depth　can　be　effectively　controlled,　allowing　for　precise　control　over　the　morphology　of　the　deposited　layers.　This　study　demonstrates　the　potential　of　this　process　to　enhance　deposition　efficiency,　reduce　thermal　input,　and　achieve　effective　shaping　control.　©　2024　The　Society　of　Manufacturing　Engineers