Rotating arm type crane

The utility model discloses a rotating arm type crane which comprises a transverse rotating beam, a lower connecting seat is fixed on the bottom surface of the middle of the transverse rotating beam, a lower supporting frame is arranged under the middle of the transverse rotating beam, an upper fixing frame is fixed in the middle of the top surface of a top frame of the lower supporting frame, and a rotating support is installed on the top surface of a top plate of the upper fixing frame. A driving motor is fixed on the upper fixing frame, a driving gear is fixed on an output shaft of the driving motor, the driving gear is meshed with an outer tooth part of an outer gear ring of the rotary support, and the lower connecting seat is fixed on the outer gear ring; transverse beams are fixed to the bottom faces of the front side and the rear side of the bottom of the lower supporting frame correspondingly, and walking trolleys are installed on the left portions and the right portions of the bottom faces of the tra