Motion refers to the movement of the mould during the moulding process; interference refers to the effect between moving parts and between moving parts and stationary parts when the injection mould processing factory customises the mould for movement. There are many forms of motion and interference elements in the structural design of injection moulds, and it is also one of the six elements in the analysis of injection moulded parts. It not only affects the structure of the injection mould, but also the normal operation of the injection mould, and the mould can be damaged by the collision of various parts, even leading to the destruction of the injection moulding equipment and the death or injury of the operator. Therefore, the factors of motion and interference should attract sufficient attention from mould designers. Motion and interference are unavoidable factors in the structural design of injection moulds, and are also the focus of the structural design of injection moulds. In the custom design of injection moulds by injection moulding processors, it is necessary to clear the various movement organizations beforehand that may produce the hidden danger of movement interference. The specific method is to find out the movement elements of the injection moulded part after moulding, then analyse whether the various movement organizations of the injection mould will produce movement interference, if it will produce interference, then take corresponding measures to prevent the phenomenon of movement interference.