Fastening tool and fastening method for ground potential fastening strain drainage bolt

The invention discloses a fastening tool and a fastening method for a ground potential fastening strain drainage bolt. The fastening tool comprises an insulating operating rod, a follow-up mechanism is fixedly installed at the bottom of the insulating operating rod, the follow-up mechanism comprises two first follow-up arms, the tops of the two first follow-up arms are rotatably and fixedly connected with the insulating operating rod, the bottoms of the two first follow-up arms are each fixedly connected with a first horizontal rod, the two first horizontal rods are each rotatably and fixedly provided with a ratchet socket wrench, sleeves at the bottoms of the two ratchet socket wrenches are used for sleeving a nut and a bolt head of the drainage bolt, when the insulating operating rod is lifted, the two first follow-up arms can control the two first horizontal rods to reversely swing around the axis of the drainage bolt, then the two ratchet socket wrenches are driven to reversely swing, and tightening opera