Folding casing preassembling and fixing device and folding casing preassembling method

The invention relates to the technical field of ship manufacturing, in particular to a folding sleeve preassembling fixing device which comprises a pipe body, one end of the pipe body is provided with a plugging end face, the other end of the pipe body is provided with a pipe opening, the pipe body comprises a first section, a second section and a third section which are sequentially connected in the axial direction of the pipe body, and the inner diameter of the first section and the inner diameter of the third section are both larger than the outer diameter of a preassembling pipe. The inner diameter of the second section is larger than the outer diameter of the folding sleeve, the length of the second section is larger than or equal to that of the folding sleeve, the pipe body is divided into a first half pipe and a second half pipe in the plane where the pipe body is located in the axial direction of the pipe body, and the first half pipe and the second half pipe are detachably connected. The invention fu