注塑成型是一个循环的过程，每一周期主要包括：定量加料—熔融塑化—施压注射—充模冷却—启模取件。取出塑件后又再闭模，进行下一个循环。注塑机操作项目包括控制键盘操作、电器控制系统操作和液压系统操作三个方面。分别进行注射过程动作、加料动作、注射压力、注射速度、顶出型式的选择，料筒各段温度的监控，注射压力和背压压力的调节等。
Injection molding is a cyclic process, each cycle mainly includes: quantitative feeding - melt plasticization - pressure injection - filling cooling - opening parts. After removing the plastic parts, the mould is closed again for the next cycle. The operation items of injection moulding machine include three aspects: control keyboard operation, electrical control system operation and hydraulic system operation. The selection of injection process action, feeding action, injection pressure, injection speed, ejection type, temperature monitoring of each section of the barrel, injection pressure and back pressure adjustment are carried out respectively.
注塑机的工作原理：与打针用的注射器相似，它是借助螺杆（或柱塞）的推力，将已塑化好的熔融状态（即粘流态）的塑料注射入闭合好的模腔内，经固化定型后取得制品的工艺过程。 一般螺杆式注塑机的成型工艺过程是：首先将粒状或粉状塑料加入机筒内，并通过螺杆的旋转和机筒外壁加热使塑料成为熔融状态，然后机器进行合模和注射座前移，接着向注射缸通人压力油，使螺杆向前推进，从而以很高的压力和较快的速度将熔料注入温度较低的闭合模具内，经过一定时间和压力保持（又称保压）、冷却，使其固化成型，便可开模取出制品。
Working Principle of Injection Molding Machine: Similar to the syringe used for injection, it is a process of injecting the plasticized melt state (i.e. viscous flow state) into the closed cavity with the help of the screw (or plunger) to obtain the product after solidification and shaping. Generally, the forming process of screw injection moulding machine is as follows: firstly, the granular or powdery plastic is added into the barrel, and then the plastic is melted by the rotation of the screw and the heating of the outer wall of the barrel. Then the machine closes the mould and moves forward the injection seat. Then, the pressure oil is injected into the injection cylinder to push the screw forward, so that the screw is very high. The melt is injected into the closed die with lower temperature by pressure and faster speed. After a certain period of time and pressure retention (also known as holding pressure) and cooling, the melt is solidified and formed, and the product can be removed from the open die.