Sectional disassembly construction process method for large arm of tower head pull rod type tower crane

The invention discloses a tower head pull rod type tower crane big arm sectional disassembly construction process method which comprises the following steps: disassembling one section or two sections of arms in front of a long pull rod of a tower head pull rod type tower crane big arm by adopting a hoisting device I, so that a 50-meter big arm is left on the tower crane, hanging a lifting hook of the hoisting device I in the middle of a fourth section of big arm, slightly lifting the big arm by a certain angle, and lifting the big arm by a certain angle; the method comprises the following steps: operating a tower head pull rod type tower crane to tighten a winch steel wire rope, dismantling a connecting shaft pin at a balance arm pull rod and a balance arm, slowly loosening the winch steel wire rope to enable a tower head to incline forwards, opening a tower head supporting short pull rod, dismantling a long pull rod by adopting hoisting equipment II, operating a winch, tightening the steel wire rope, pulling