Multi-station up-and-down undercut machine for inner container machining

The invention relates to a multi-station up-and-down undercutting machine for liner processing, which comprises a machine table fixedly mounted on a working area; the rotating mechanism is mounted on the machine table; the rotary table is fixedly connected with the rotating mechanism so as to rotate along with the rotating mechanism; the mold mechanism is mounted on the machine table and is connected with the rotating mechanism and the rotary table so as to support a mold; the limiting mechanism is mounted on the machine table; the four undercut mechanisms are installed on the machine table, surround the die mechanisms and are connected with the rotary table, so that the undercut mechanisms and the rotary table synchronously work in a crank rocker mode, and the four undercut mechanisms rotate along with the rotary table and sequentially carry out undercut work on dies on the die mechanisms; multi-station simultaneous work is adopted, the undercut work of different corners can be greatly improved, the upper st