The invention discloses an insulator lightning protection device with an adjustable parallel gap. The insulator lightning protection device comprises an insulator, wherein a grounding side electrode and a lead side electrode are fixed at the two ends of the insulator; the grounding side electrode and the lead side electrode are claws with at least three claw fingers; the claw fingers on both sides of the insulator are the same in quantity, and are arranged correspondingly. The insulator lightning protection device with the adjustable parallel gap is simple in structure, and is convenient to install. The claw fingers of the lead side electrode or the grounding side electrode are movably connected, and the claw fingers move along a plane where the axis of the insulator is positioned, so that the distance between the grounding side electrode and the lead side electrode can be adjusted in order to adapt to insulators of different lengths.