Vacuum screw extruder

The invention discloses a vacuum screw extruder which is composed of a vacuum extrusion mechanism, a raw material uniform adjusting mechanism and a forming and pore forming mechanism. The extrusion mechanism is composed of an upper-level sealing spiral reamer, a vacuum material receiving chamber, a mud beating plate, a mud cylinder, a reamer shaft, a single-screw conveying reamer set and a three-screw reamer, wherein the mud cylinder, the reamer shaft, the single-screw conveying reamer set and the three-screw reamer are arranged on the lower portion of the vacuum material receiving chamber, and the single-screw conveying reamer set is arranged on the reamer shaft. The raw material uniform adjusting mechanism is composed of a material evening groove, a mud blocking bar, an outlet mud flowing speed adjusting bolt and an outlet mud flowing speed adjusting block. The forming and pore forming mechanism is composed of an outlet, a machine head, a core rod and a core head, wherein the core rod and the core head are arranged on a core frame. The stress of an extrusion section of the vacuum screw extruder is more uniform and more balanced, the raw material extruding speed can be adjusted, under the condition of the same yield, the rotating speed can be reduced, abrasion is relieved, the extruding efficiency is improved, loads are reduced, and energy is saved.