Sheet type centering device with controllable size of external diameter

The utility model discloses a sheet type centering device with a controllable size of an external diameter. The sheet type centering device comprises an upper main body and a lower main body movably connected with the upper main body. An upper spring and a lower spring are respectively arranged on the lateral faces of the upper main body and the lower main body; an upper sliding ring is arranged between the both ends of the upper spring, and a lower sliding ring is arranged between the both ends of the lower ring; and a centering ring is connected between the upper sliding ring and the lower sliding ring. The sheet type centering device provided by the utility model is simpler in structure and is in a split type structure that the upper main body and the lower main body are movably connected. A centering sheet is deformed by separation or approach of the upper main body and the lower main body, so that the size of the external diameter of the sheet type centering device provided by the utility model can be ad