The invention discloses a bridge telescopic device anchoring structure, which belongs to the technical field of bridge structure telescopic devices, and comprises a side beam, a connecting steel plate, an anchoring steel plate and an embedded bar, wherein the connecting relationship is as below: the connecting steel plate is arranged on the side beam and is parallel to the side beam; the anchoring steel plate penetrates through a rectangular through hole of the connecting steel plate; the anchoring steel plate can freely move along the connecting steel plate through the cooperation of a T-shaped vertical part of the anchoring steel plate and the rectangular through hole of the connecting steel plate; the anchoring steel plate is welded with the embedded bar. According to the bridge telescopic device anchoring structure, free telescoping can be realized, the service life of the modular telescopic device is prolonged, and the safety problem of driving a car on a bridge caused by the damage of the telescopic device is avoided.