Corrugated steel cofferdam hollow digging pile and manufacturing technique thereof

The invention relates to a corrugated steel cofferdam hollow digging pile and a manufacturing technique thereof. The corrugated steel cofferdam hollow digging pile comprises a cofferdam, a steel bar concrete hollow pile body in the cofferdam, and a pier stud above the steel bar concrete hollow pile body. The cofferdam is provided with a plurality of circular corrugated steel wallboards arranged in a layered mode. The diameters of the circular corrugated steel wallboards arranged in the layered mode are decreased sequentially from top to bottom. A transverse corrugated steel connection plate is arranged in a gap between every two adjacent circular corrugated steel wallboards. The manufacturing technique of the corrugated steel cofferdam hollow digging pile comprises the steps that a hoisting excavator excavates the first section of pile hole, and the first layer of circular corrugated steel wallboard is arranged; the multiple layers of circular corrugated steel wallboards with the diameters decreasing from top