The above is big barrel mould and barrel lid mould, which introduces the design process of the injection mould in detail. It mainly uses 3D software to design, conduct 3D modeling according to the product, and analyze the model. The structure consists of sliding block, inclined top block and demoulding. The plastic part is the shell, the design process of the gating system uses multi-cavity side gates to design and carry out the necessary calculation and structural design of the molded parts. Finally, Autocad completed the production of processing engineering drawings, and considered various factors in the design.