Pipeline connecting device

The utility model discloses a pipeline connecting device. The device comprises a plurality of adjacently arranged pipelines, inner pipes located on the inner sides of the pipelines are concentricallyconnected between the adjacent ends of the adjacent pipelines. A cylindrical ring surrounding the circumference of the inner pipe is arranged in the middle of the inner pipe; the wall thickness of thecylindrical ring is greater than or equal to that of the pipeline; the two side ends of the cylindrical ring are attached to the adjacent ends of the pipelines on the two sides of the cylindrical ring respectively. A plurality of screws are evenly distributed on the periphery of the cylindrical ring in the radial direction of the cylindrical ring. Wherein a pressing plate with a fan-shaped section penetrates through the screw rod, a locking nut used for locking the pressing plate is further arranged, fan-shaped convex blocks with right-angled trapezoidal sections are symmetrically arranged atthe two ends of the pressi