The utility model discloses a safety-belt telescopic suspension device used for transformer substation incoming and outgoing line casing pipe operation. The device comprises a fixing iron plate and expansion bolts. The fixing iron plate is in a rectangle shape. The expansion bolts are inserted into through holes of four corners of the fixing iron plate. The device is characterized in that a middle and upper portion of the fixing iron plate is provided with a casing pipe which is vertical to the fixing iron plate; a telescopic pipe is arranged in the casing pipe; a positioning bolt of the telescopic pipe is arranged on the casing pipe; an outer end portion of the telescopic pipe is fixed with a safety belt suspension ring. Because the safety-belt telescopic suspension device is fixed and installed on an adjacent wall, an installation safety coefficient is high and reliability is good and a problem that there is no reliable safety belt suspension point during working is solved. Simultaneously, safety of working personnel during the working is effectively increased; operation is normative; and quality and efficiency of the working are increased. The structure is simple and cost is low. The device can be used for a long time after one-step installation. The suspension point position can be stretched and changed. The device can adapt to working of different positions.