This article primarily focuses on the transmission system of plastic extruders, utilizing frequency converters to drive permanent magnet synchronous motors. It elaborates on the advantages of permanent magnet synchronous motors over conventional three-phase asynchronous motors, including high efficiency, high power factor, large starting torque, high precision, wide speed range, simple structure, and small size. Additionally, through parameter optimization and adjustment of the Toshiba frequency converter VF-AS3, the operational efficiency of the permanent magnet synchronous motor is enhanced, thereby assisting customers in reducing costs, conserving energy, and ensuring smooth operation of the extruder.