The invention discloses a prefabricated tensioning working platform for tensioning of cap beams of bridge piers. The prefabricated tensioning working platform comprises a beam body and cantilever beams arranged above the beam body, wherein an upper tie beam and a lower tie beam are respectively arranged above and below one end of the beam body; suspenders are respectively arranged at both sides ofthe end of the beam body; the upper tie beam and the lower tie beam are fixedly connected with the suspenders to form a fixed frame which is fixed at the end of the beam body; a tie is arranged on the top of the other end of the beam body; one end of each cantilever beam is fixedly connected with the upper tie beam; the middle part of each cantilever beam is arranged on the tie; and a transversebearing beam is fixed to the bottom of the other end of each cantilever beam. The structure of the prefabricated tensioning working platform for tensioning of the cap beams of the bridge piers has theadvantages of simple construction, convenient mounting and dismounting, elimination of an overhead working procedure, recycled utilization, saving of a large amount of steel, high adaptability and lower investment of engineering costs. At the same time, the prefabricated tensioning working platform has the advantages of ensuring the construction safety, improving the operation safety and workingefficiency and reducing the labor intensity. Each set of formwork can be recycled so as to reduce the costs, and can be popularized in construction.