IncombinationwiththeprocesstechnologyandequipmentatTangsteelColdRollingMill’s3~#galvanizedline,themechanismofdefect-formationofthestripsurfaceinthehotdipgalvanizedcoatinghasbeenanalyzed.Throughaseriesofreformabouttechnologyandequipmentgoodsolvedthedefectshasbeenfocusedoninthispaper.Thestripsurfacequalityinthehotdipgalvanizedcoatinghasbeenimprovedalot.