The invention discloses an electrified overhead line system cantilever prefabrication platform. The electrified overhead line system cantilever prefabrication platform comprises one set of cantilever measurement and cutting platform, one set of positioning pipe prefabrication platform, two sets of cantilever prefabrication platforms and one set of recheck platform, wherein the cantilever measurement and cutting platform, the positioning pipe prefabrication platform, the cantilever prefabrication platforms and the recheck platform form one whole set of complete machining chain, and synchronously satisfy the requirements for integration of measurement, machining and recheck. The electrified overhead line system cantilever prefabrication platform performs control according to the procedures of cantilever cutting, part prefabrication, fastening, selective examination and recording, adopts a mode of signing, hand-over, recording and filing for each procedure, performs the quality control in a workshop, solves the problem of difficulty in controlling the site construction quality, and realizes unified mounting, fastening construction and checking in factories, and guarantees safety, high quality and ordered control. A remarkable effect is achieved in actual application.