The invention belongs to a reinforcing bar banding stretching rack for a pre-stressed concrete prefabricated box girder. The reinforcing bar banding stretching rack comprises a reinforcing bar banding rack and a stretching rack. The reinforcing bar banding rack is formed by connecting multiple sets of single supports in a spacing distance mode through reinforcing pillars and web reinforcing bar pillars. Each single support is composed of two banding supports and a transverse connection beam. The two hypotenuses of the two banding supports are arranged correspondingly, and the two banding supports are of the shape of a right triangle. The two banding supports are transversely fixedly connected in a spacing distance mode through the transverse connection beam at the bottoms. The stretching rack is composed of a main stretching rack, a vice stretching rack, upper stretching support pillars and lower stretching support pillars. The main stretching rack is located on one side of the reinforcing bar banding rack. The vice stretching rack is located on the other side of the reinforcing bar banding rack. The main stretching rack and the vice stretching rack are connected into a whole through the upper stretching support pillars and the lower stretching support pillars in four corners. The reinforcing bar banding stretching rack has the advantages of being simple and practical in structure, capable of adapting to various prefabricated box girder structure operations, capable of calibrating and straightening a reinforcing bar grid frame, beneficial to banding operations, good in efficiency and quality, low in production cost, convenient to disassemble and assemble, safe in use and good in use effect.