Mechanical clamping and pressing type steel ring bell and spigot joint of plastic pipe fitting

The utility model provides a mechanical clamping and pressing type steel ring bell and spigot joint of a plastic pipe fitting. The pipe fitting comprises a plurality of pipe fitting units, each pipe fitting unit comprises a PE lining layer, a steel wire reinforcing layer and a PE outer sleeve layer from inside to outside. A connecting structure is arranged between every two adjacent pipe fitting units. The connecting structure is provided with an inserting opening steel ring, an inserting opening steel ring and two steel clamping rings. The socket steel ring is provided with a large head and asmall head; the outer diameter of the small head is consistent with the inner diameter of the pipe fitting unit; the outer diameter of the large head is consistent with that of the pipe fitting unit;the socket steel ring is provided with a large end and a small end; the outer diameter of the small end is consistent with the inner diameter of the pipe fitting unit; wherein the large end is connected with the large end, th