Roundness maintaining instrument for suction bucket and central cylinder of offshore wind power jacket

The invention provides a roundness maintaining instrument for a suction bucket and a central cylinder of an offshore wind power jacket. The roundness maintaining instrument comprises a central ring, a connecting beam, a transition connecting plate, a single-head screw, a first nut connecting block, a second nut connecting block, a transition connecting pipe, a double-head screw, a connecting block, an arc-shaped plate and a positioning bolt, two ends of the connecting beam are respectively welded and fixed with the central ring and the transition connecting plate; the polished rod end of the single-head screw is welded and fixed with the transition connecting plate, and the threaded end is in threaded connection with one end face of the first nut connecting block; the other end face of the first nut connecting block is fixedly welded to one end of a transition connecting pipe, and the other end of the transition connecting pipe is fixedly welded to one end face of the second nut connecting block. The other en