The invention discloses a method for wrapping a cable by an overhead exposed cable automatic wrapping robot. The method comprises the steps of adjusting a lifting mechanism to drive a buckle mechanismto move towards the bottom of a rack until a cable cannot be prevented from entering a region by the buckle region; introducing an insulation skin to a feeding mechanism by an insulation skin guide mechanism at the top of the rack, and installing the insulation skin on a feeding support mechanism by guidance after the insulation skin is clamped into a travelling mechanism of an adjacent feeding mechanism; lifting the overhead exposed cable automatic wrapping robot to a part above the cable by an insulation support piece, allowing the cable to enter the overhead exposed cable automatic wrapping robot from an inlet end, and guiding the cable to enter the feeding support mechanism and simultaneously be in contact with the travelling mechanism by the guidance of a cable guide mechanism; starting the feeding support mechanism and the lifting mechanism, closing the feeding support mechanism after the feeding support mechanism is fastened, and closing the lifting mechanism when the buckle mechanism gets near to the feeding support mechanism; and starting the feeding mechanism, the travelling mechanism and the buckle mechanism so that the insulation skin enters the buckle mechanism to wrap the cable.