The invention relates to a construction method of a corbel and steel truss bracket of a wide-span upper crossbeam of an extra-high cable bent tower, and belongs to the technical field of the construction of buildings. The construction method comprises the following steps of mounting embedded parts, mounting lifting equipment, lifting steel truss, mounting corbel supports, and integrally lifting the steel truss and the corbel supports to right places and performing fixing. According to the construction method of the corbel and the steel truss bracket of the wide-span upper crossbeam of the extra-high cable bent tower provided by the invention, the difficult problem that a construction method of a console-type bracket is often adopted by conventional upper beams, and the deviation of a large-cantilever flexible cable bent tower is easy to generate in a general wide-span non-console corbel bracket in the constructing process of the wide-span upper beam, so that the construction quality is influenced is effectively solved, the construction method disclosed by the invention has the characteristics of being low in investment, short in construction cycle, low in security risk, and the construction process is orderly and controllable, and reference is provided for similar bridge construction.