The expansion joint is mainly composed of a body, a telescopic sleeve, a gland, a sealing ring and a bolt. The telescopic body, telescopic sleeve and gland are made of 16MnR, and the sealing ring is made of NBR sealing, which has good water tightness and air tightness. Supporting the use of expansion joints and butterfly valve, the flange surface between the axial extension and radial angular displacement, position and angle to compensate the error of pipe flange, eliminate the internal stress caused by pipeline pipeline temperature, bring great convenience to the installation and maintenance of pipelines.