An adsorption type guardrail used for transformer substation overhaul relates to the transformer substation overhaul field. During the detection and maintenance operation engineering of the transformer substation electric appliance equipment, formerly a red cloth curtain is hung on a protection screen to warn and stop the people with no duty to get close, the duration of the process of tying and the like is longer, the red cloth curtain is easy to fall off, and the patrol inspection is not convenient. The adsorption type guardrail of the present invention comprises two shielding boxes absorbedon two protection screen cabinet doors respectively, an automatic telescoping rail belt is arranged between the two shielding boxes, and a caution layer used for warning the people not to get close is arranged on the surface of the rail belt. The adsorption type guardrail of the technical scheme is simple in structure, is convenient to operate, when being used, one shielding box absorbs on one protection screen cabinet door, the rail belt is tensioned to absorb the other one shielding box on the other protection screen cabinet door, so that the absorption is firm. When not being used, the rail belt retracts automatically, and the occupation space of the whole guardrail device is small. By the caution effect of the rail belt, the whole adsorption type guardrail is good in caution effect, low in cost and small in storage space, and is safer and more reliable.