Stay cable bridge structure of high-speed railway and construction method

The invention discloses a construction method for a stay cable bridge of a high-speed railway, which is characterized in that a plurality of section beams are prefabricated and stored in advance through a double-production-line prefabricating yard, so that after main tower construction is completed, the main tower can be quickly placed on a sliding track for tensioning connection of adjacent section beams and tensioning connection with prestressed steel cables, and the overall construction efficiency is improved; the construction period is shortened. As the segmental beams are prefabricated in advance and all hoisted to the sliding rails, and the at least three adjacent segmental beams are tensioned and connected through the connecting mechanisms, compared with an existing mode that the adjacent segmental beams are connected in sequence, higher efficiency is achieved, and therefore the segmental beams of side spans and part of main spans can be rapidly assembled to form a bridge floor; time is saved for later