Branch pipe connecting structure of plastic-lined pipeline

The invention discloses a plastic-lined pipeline branch pipe connecting structure in the field of electric power and petrochemical engineering, which mainly comprises a main pipe, a branch pup joint, a connecting sleeve, a sealing connecting cover and a connecting flange, the branch pup joint is a plastic-lined pipeline with a flange at one end and an elbow at the other end, and the end, with the elbow, of the branch pup joint extends into the main pipe; the branch pup joint is connected with the sealing connecting cover through the central hole; one end of the connecting sleeve is welded to the main pipe, the other end of the connecting sleeve is welded to the connecting flange, and the connecting flange is connected with the sealing connecting cover. According to the invention, the medicament to be injected is directly led to the center of the main pipe by adopting the branch pup joint with the elbow, and the injected medicament flows, is diluted and lightened in the main pipe along with the main flow of th