Extrusion screw for extruder

The utility model discloses an extrusion screw rod for an extruder. The extrusion screw rod comprises a rotating shaft connecting column, a material limiting plate, a connecting section, a threaded side through hole, a material mixing threaded groove, a mixing threaded groove, a mixing section, an extrusion section, a material conveying threaded groove and a threaded bottom section. The material limiting plate is arranged on the inner side of the rotating shaft connecting column, the phenomenon that materials remain in the extruder during working can be avoided, the diameter of the mixing section is larger than that of the connecting section, the mixing degree of the mixing threaded groove in the surface of the mixing section to the materials can be increased, and the working efficiency isimproved; the threaded side through holes are formed in the inner side walls of the material mixing threaded grooves, and some materials mixed by the material mixing threaded grooves can flow back into the adjacent material