As　a　new-type　welding　heat　source,　cross-coupling　arc　(CCA)　is　able　to　realize　the　decoupling　control　of　heat　transfer,　force　transfer　and　mass　transfer　in　welding　process.　However,　the　physical　mechanism　of　CCA　still　remains　unclear,　restricting　the　application　and　optimization　of　CCA　welding　technology.　In　order　to　explore　the　laws　and　causes　of　polar　zone　phenomena　(PZP)　in　CCA　welding　and　based　on　the　electromagnetic　field　effect　of　the　inter-wire　arc　(IWA)　itself,　the　novel　methods　of　an　electrified　tungsten　rod　crossing　a　free　burning　arc　and　an　electrified　parallel　plate　capacitor　applied　to　both　sides　of　a　burning　arc　were　designed　to　decouple　the　electromagnetic　coupling　field　generated　by　the　IWA.　The　arc　shape　during　the　experiments　was　recorded　by　a　high-speed　camera　system　in　real　time.　The　results　show　that　the　laws　of　PZP　in　CCA　welding　were　supplemented　and　summarized.　When　the　main　arc　polarity　is　direct　current　electrode　negative,　the　main　arc　deflects　to　the　IWA　cathode,　and　when　the　main　arc　polarity　is　direct　current　electrode　positive,　the　main　arc　deflects　to　the　IWA　anode.　More　importantly,　the　causes　of　PZP　were　found.　The　magnetic　field　generated　by　the　IWA　and　the　limitation　in　bottom　area　and　position　of　the　main　arc　tungsten　electrode　are　the　causes　of　PZP.　The　direction　control　of　PZP　could　be　achieved　by　adjusting　the　polarities　of　the　IWA　or　the　main　arc　and　the　PZP　effect　could　be　reduced　by　changing　the　current　direction　in　the　IWA.