The utility model discloses a prestressed bridge stretching bed, and belongs to the filed of architectural engineering. The prestressed bridge stretching bed comprises a bottom plate, a top plate, an external fastening device, two panels, a transverse plate and lifting lugs, wherein the two panels are vertical to the bottom plate, and the top plate, the transverse plate and the bottom plate are sequentially arranged in parallel from top to bottom and positioned between the two panels; a rectangular long groove is formed in the middle of each panel, and the external fastening device comprises a main plate, an auxiliary plate, a bottom connecting plate and two reinforcing plates; the main plate, the auxiliary plate, the bottom connecting plate and the two reinforcing plates form a groove-shaped cavity with an opening at the top, and steel bar perforating holes with the same size are formed in the corresponding positions of the main plate and the auxiliary plate; the main plate is fixedly arranged in the middle of the panel. The prestressed bridge stretching bed provided by the utility model has the advantages of high flexural strength, simple structure, convenience in operation, great reduction in construction period and easiness in popularization, and can be transported to the site in accordance with the construction needs, and adopts an external limit device to position finish-rolled screw-thread steel bars.