Tower-passing construction method for main tower internally-penetrating type steel box girder cable bearing bridge

The invention relates to a tower-passing construction method for a main tower internally-penetrating type steel box girder cable bearing bridge. The tower-passing construction method comprises the steps that a to-be-installed steel box girder is divided into side steel box girder sections, a middle steel box girder section and a steel cross beam section; the side steel box girder sections and the middle steel box girder sections are sequentially hoisted to the slide way girder on the main span side; the side steel box girder sections and the middle steel box girder sections are longitudinally pushed to the designed positions towards the side span sides correspondingly, and are spliced from front to back to form side steel box girders and middle steel box girders; and the multiple steel cross beam sections are hoisted to the positions between the corresponding side steel box girders and the corresponding middle steel box girders, butt joint is completed, and the whole side span steel box girder is formed. The