Small-spatial construction method for steel anchor beam anchoring zone of cable-stayed bridge upper pylon

The invention relates to a small-spatial construction method for a steel anchor beam anchoring zone of a cable-stayed bridge upper pylon. The small-spatial construction method comprises the following steps: pre-casting a scaffold all-in-one device in a steel inner formwork; hoisting the steel inner formwork to a to-be-poured section of an upper pylon inner chamber, supporting the folded scaffold all-in-one device on the steel anchor beam, and mounting a scaffold board on the scaffold all-in-one device; unfolding the scaffold all-in-one device, and separating the scaffold all-in-one device from the steel anchor beam; hoisting up the steel inner formwork; repeating steps b to d. As the scaffold all-in-one device in an unfolding-folding design is pre-mounted on the steel inner formwork, and the scaffold all-in-one device is unfolded during hoisting, and is folded and supported on the steel anchor beam when the scaffold board is positioned and needs to be mounted, massive work of embedding embedded parts in the inner chamber is avoided during the construction in the steel anchor beam anchoring zone of the upper pylon on a cable tower, the repair problem of the inner chamber is avoided after the construction of the upper pylon on the cable tower, and massive labor and time consumption is avoided. The small-spatial construction method has the characteristics of high safety, convenience and rapidness and is suitable for overhead bridge construction.