The invention discloses a construction method for a long-span overhung specially-shaped limit exceeding structure steel corridor. The method includes the following steps that firstly, the steel corridor is divided into construction units, wherein the inner part of a corridor structure and middle strip blocks of an upper steel structure of a corridor overhung part are classified as the first construction unit, the remaining part of the corridor overhung part is classified as the second construction unit, and a corridor suspension part is classified as the third construction unit; secondly, a high-altitude bulk assembly method and a cantilever installation method are adopted for finishing construction of the first construction unit on a floor panel of a tower A; thirdly, construction of the second construction unit is finished through integral lifting; and fourthly, construction of the third construction unit is finished through sliding after integral lifting. The high-altitude bulk assembly technology, the integral lifting technology, the sliding after integral lifting technology and the like are applied, work hours are reduced, the material cost and equipment cost are saved, and the requirements for integral control over multiple aspects of the construction process, the quality, the safety, the schedule, the cost and the like are met.