Construction method of cast-in-place box girder cable-stayed bridge

The invention relates to the field of bridge building construction, in particular to a construction method of a cast-in-place box girder cable-stayed bridge. A vertically-through stay cable lifting channel is reserved in the central axis position of the cable bent tower body section, and a stay cable bearing platform for mounting a stay cable is reserved on the cable bent tower; then box girders and stress box girders with bridge end mounting positions are symmetrically built on the two sides of the cable bent tower; finally, two stay cables with the same length are unfolded on the bridge floor on the two sides of the cable bent tower body section at the same time, the tower ends of the two stay cables are connected together at the bottom of the stay cable lifting channel, and the tower ends of the stay cables connected together are lifted and installed on a stay cable bearing platform; and the bridge end of the stay cable is installed at the bridge end installation position of the stress box girder. Accordin