The stainless steel expansion joints is a flexible, thin-walled, transversely corrugated device with telescopic function. It is composed of a metal bellows and components. The working principle of the bellows is mainly to use its own elastic deformation function to compensate the axial, angular, lateral and combined displacements of the pipeline due to thermal deformation, mechanical deformation and various mechanical vibrations. The compensation function is resistant to The functions of pressure, sealing, corrosion resistance, temperature resistance, impact resistance, vibration reduction and noise reduction can reduce pipeline deformation and increase pipeline service life. The stainless steel bellows is widely used in automatic control and measuring instruments, vacuum technology, machinery industry, electric power industry, transportation and atomic energy industry as sensitive components, damping components, compensation components, sealing components, valve components and pipeline connectors. And other fields.