The invention discloses an anti-static device. The anti-static device comprises a sleeve arranged on a stair guardrail and a protective bush arranged on the sleeve and provided with a telescopic property; a positioning hole is formed in the center of the sleeve; the protective bush is formed through sequential sleeve joint of a plurality of telescopic cylinders, and the front-stage telescopic cylinder is sleeved with the rear-stage telescopic cylinder; the rear end of the telescopic cylinder located at the outermost stage is fixed into the positioning hole, the stair guardrail is located in the innermost-stage telescopic cylinder, the multiple telescopic cylinders are sequentially pulled out, and the stair guardrail is wrapped by the multiple telescopic cylinders; and the sleeve is made of an insulation material, and the protective bush is made of an insulation material. The anti-static device is simple in structure and convenient to manufacture and mount, the effect of effective prevention of induced electricity can be achieved, and thus work personnel are protected against falling and hurting caused due to induced electricity influence in the process of stair up climbing; and through the freely-telescopic protective bush, convenience and effectiveness are high, and while the service life is guaranteed, maintenance cost is reduced.