The utility model relates to a be used for transmission line group tower to embrace pole with round pin axle connecting device, characterized by, including single, the double ear plate connecting piece that matches each other, the single -lug plate connecting piece include bulge and fixed part, the double ear plate connecting piece include recess and installation department, the bulge of single -lug plate connecting piece and the recess phase -match of double ear plate connecting piece, fixed part and installation parts bie are connected in the angle steel. The utility model discloses rationalin infrastructure, convenient to use has realized the round pin axle and has been connected with the firm of angle steel, overcomes because angle steel shape structure is special, can't be applicableto the defect of round pin axle. The holistic straightness of hanging down of armful pole has been guaranteed to the connection pattern of round pin axle, and simple to operate, the easy maintenanceare applicable to the use under the on -the -spot abominable operating condition. A simultaneously, make armful pole the stress more reasonable for embracing pole standard joint connection increases substantially and embraces the pole equipment straightness that hangs down.