A　method　of　controlling　droplet　transfer　by　plasma　arc　was　proposed　to　solve　the　problem　that　cathode　spot　force　hindered　the　transition　of　cathode　droplet　under　high　current　of　twin-wire　indirect　arc　(TWIA)　in　skew-coupling　arc　(SCA)　welding.　The　effects　of　the　plasma　arc　on　droplet　transfer　were　analyzed　from　the　perspectives　of　plasma　arc　current　(PAC)　and　plasma　gas　flow　rate　(PGFR).　The　current-voltage　waveform,　arc　shape　and　the　transition　process　of　droplet　were　studied　by　using　an　electric　signal　and　high-speed　camera　acquisition　system.　The　results　show　that　controlling　droplet　transfer　by　the　plasma　arc　is　feasible　and　effective　in　the　SCA　welding.　With　the　increase　of　the　PAC,　the　degree　of　the　plasma　arc　deflection　increased,　and　increasing　the　PGFR　has　a　shrinkage　effect　on　the　top　of　the　SCA.　Increasing　the　PAC　or　the　PGFR　made　the　TWIA　current　vary　in　a　small　range,　and　the　plasma　arc　voltage　increase.　Increasing　the　PGFR　is　more　effective　to　promote　the　transition　of　cathode　droplet　than　increasing　the　PAC,　because　the　plasma　fluid　force　of　the　TWIA　on　cathode　droplet　is　enhanced　by　the　double　axial　thrust　of　the　plasma　arc　and　the　TWIA.　The　cooling　effect　of　the　plasma　gas　on　anode　droplet　weakens　the　promoting　effect　of　the　plasma　gas　on　the　transition　of　anode　droplet.　The　existence　of　the　fluid　beam　hanging　at　the　cathode　wire　is　important　to　improve　the　transition　of　cathode　droplet.　The　PGFR　and　the　PAC　could　be　cooperatively　adjusted　to　promote　the　transition　process　of　anode　and　cathode　droplet.