The invention discloses a star extruder, which comprises a host driving device and a feeding segment, a feed cooling segment, a star plasticizing and extruding segment, and a pressure-charging filtration device, which are connected to the host driving device in sequence. The feed cooling segment comprises a feed screw cylinder and a feed screw. The star plasticizing and extruding segment is composed of a plasticizing segment thread insert, a main plasticizing screw, and a small plasticizing screw, wherein one end of the plasticizing segment thread insert is fixedly connected to the feed screw cylinder, and the other end is connected to the pressure-charging filtration device; the main plasticizing screw is limited in the center of the plasticizing segment thread insert and connected to the feed screw and the host driving device in sequence; the inner wall of the plasticizing segment thread insert is provided with a smooth C-shaped groove for limiting the small plasticizing screw at the side face of the main plasticizing screw for connection; the surfaces of the main plasticizing screw and the small plasticizing screw are provided with corresponding spiral gear profiles, and the main plasticizing screw drives the small plasticizing screw to perform engagement operation; and the feed cooling segment is connected to a reused material recovery device. The star extruder has functions of material plasticizing, pressure-charging filtration and extrusion, and on-line reused material recovery, and is good in plasticizing effect, low in energy consumption and large in yield.