An expansion joint made of a bellows made of metal bellows. It can stretch along the axis and allow a small amount of bending. Figure 2[bellows expansion joint] is a common axial bellows expansion joint used for axial length compensation in a pipe. A protective rod or a protective ring is arranged at both ends of the bellows, and a guide bracket is arranged at the two ends of the pipe connected with the utility model. In addition, there are corner type and transverse expansion joints, which can be used to compensate for the corner deformation and lateral deformation of the pipe. The expansion joint has the advantages of space saving, material saving, easy standardization and mass production, and the disadvantage is that the service life is short. Bellows expansion joints are generally used for pipes of low temperature and pressure and of shorter length. With the development of bellows technology, the application of such expansion joints is expanding.