Three-layer co-extrusion polyester film structure with two-way stretching function

The utility model discloses a three-layer co-extrusion polyester film structure with a two-way stretching function, which belongs to the technical field of polyester film processing equipment and comprises a mounting seat, supporting plates are arranged on two sides of the bottom end of the mounting seat, a threaded rod is rotatably connected to the bottom end of the mounting seat, and a plurality of sliding openings are formed in the mounting seat in a penetrating manner. The multiple sliding openings are internally connected with positioning plates through guide mechanisms, linkage mechanisms are arranged between the multiple positioning plates and the threaded rod, the upper ends of the positioning plates penetrate through the side walls of the sliding openings to extend to the outside and are provided with bearing plates, the bearing plates are provided with fixing mechanisms, and the upper ends of the threaded rods are provided with cooling mechanisms. A driving mechanism is arranged at the bottom end of