The invention discloses an extruding screw rod of a plastic extruder. The extruding screw rod comprises an external screw rod body and an internal screw rod body, wherein the external screw rod body comprises a first screw rod part and a first handle part; and a power output shaft serves as the first handle part. According to the extruding screw rod, the internal screw rod body is arranged insidethe external screw rod body in a sleeving manner, a moving screw rod serves as the external screw rod body, and a fixed screw rod serves as the internal screw rod body, so that plastic positioned on the outer side of the external screw rod body can enter an extruding channel after being completely molten; accordingly, a better plasticizing effect can be achieved on the plastic in a machine barrel;through such a structure that the internal screw rod body and the external screw rod are coaxially arranged, the plastic can move out of the extruding channel along a second screw thread of the internal screw rod body after being completely molten; and compared with the prior art, the extruding screw rod disclosed by the invention is higher in extruding efficiency.