模具的结构虽然由于塑料品种和性能、塑料制品的形状和结构以及注射机的类型等不同而可能千变万化，但是基本结构是一致的。模具主要由浇注系统、调温系统、成型零件和结构零件组成。其中浇注系统和成型零件是与塑料直接接触部分，并随塑料和制品而变化，是塑模中最复杂，变化最大，要求加工光洁度和精度最高的部分。
Although the structure of the mold may vary greatly due to the variety and performance of the plastic, the shape and structure of the plastic products and the type of the injection machine, the basic structure is the same. The mold is mainly composed of pouring system, temperature regulating system, forming parts and structural parts. The pouring system and molding parts are the parts which are in direct contact with the plastics and change with the plastics and products. They are the most complex and changeable parts in the plastic mold, which require the highest processing finish and precision.
注塑模具由动模和定模两部分组成，动模安装在注射成型机的移动模板上，定模安装在注射成型机的固定模板上。在注射成型时动模与定模闭合构成浇注系统和型腔，开模时动模和定模分离以便取出塑料制品。为了减少繁重的模具设计和制造工作量，注塑模大多采用了标准模架。
The injection mold is composed of a moving mold and a fixed mold. The moving mold is installed on the moving template of the injection molding machine, and the fixed mold is installed on the fixed template of the injection molding machine. During the injection molding, the movable mold and the fixed mold are closed to form the pouring system and the mold cavity. When the mold is opened, the movable mold and the fixed mold are separated to take out the plastic products. In order to reduce the heavy workload of mold design and manufacturing, most injection molds use the standard mold base.