The invention relates to the field of maintenance operation on an electric pole and tower, and in particular relates to a direct-current 500kV circuit lower composite insulator flexible ladder which comprises upper hanging points, a lower single hook, a hanging belt and a pedal cross tie. The direct-current 500kV circuit lower composite insulator flexible ladder is characterized in that the upper hanging points are dual hanging points; the two upper hanging points are connected by an insulation plate bar; the lower single hook has a width of 150-200mm, and the pedal cross tie has a width of 300-350mm; each upper hanging point comprises a hanging body, a hanging belt winding shaft and a winding shaft positioning device; the hanging body corresponding to a cross arm is provided with an opening; the hanging belt winding shaft is movably connected with the hanging body; one end of the hanging belt winding shaft is a polygonal head part, and the other end of the hanging belt winding shaft is connected with the winding shaft positioning device; the hanging belt winding shaft is provided with a through groove; and the end part of the hanging belt is fixed on the through groove. Compared with the prior art, the direct-current 500kV circuit lower composite insulator flexible ladder provided by the invention has the beneficial effects that a dual-hanging-point structure is adopted, the rotation prevention performance of the flexible ladder is increased, the rotation and shaking for the overhauling personnel in descending the ladder are relieved, and the falling down and casualty accidents of the overhauling personnel caused by panic is prevented.