Deep-water bucket foundation and underwater mounting method thereof

The invention discloses a deep-water bucket foundation and an underwater mounting method thereof. The deep-water bucket foundation comprises a hollow bucket body; the bucket body has the top end and the bottom end which are opposite; a connector which is connected with a drill pipe feeding tool is arranged at the top end; the drill pipe feeding tool can apply axial and circumferential loads to the bucket body provided with the connector; a spiral wing plate is arranged on the side wall of the bucket body; the rotation direction of the spiral wing plate is identical with the rotation direction of the drill pipe feeding tool; the spiral wing plate has the upper starting end and the lower stop end which are opposite; the lower stop end is spaced from the bottom end by the preset distance; drain valves are further arranged on the bucket body and communicate with the inside of the bucket body; and suspension pieces are further arranged on the bucket body. With the deep-water bucket foundation and the underwater mounting method thereof, through matched operation of a derrick of a deep-water drilling platform and a drill pipe, deep-water underwater mounting operation can be performed on the bucket foundation, and the requirements of deep sea mounting and construction can be met.