Plastic industry is one of the world's fastest-growing industrial .In everyday life almost everyday use plastic products, most of these products by injection molding method production. As is known to all, injection molding process is making all sorts of shapes of product and low-cost production complex shape product manufacturing process.The graduation design of the main content is XueBi lid injection mold design. From plastic material performance analysis, according to the basic plastic parts,shape and size of the rational selection of injection molding method. Through the analysis of the technology of plastic parts for mold production conditions and with manufacture level of mastery and work out forming process card. In setting out after forming process card to begin die structure design.One die structure design process includes: cavity number and positioning,die structure form design, dynamic model and decide the determination of forming parts size mold, gating system forms and sizes, stripping the sure way to determine, tempering and exhaust system identified, formwork choice to stay above the steps are done, started drawing die structure sketches, according to the concrete size checking injection molding tool and injection molding machine,and the relevant dimensions of verification and calculation process parameters. Carries on the preliminary review after some issues identified and fix, then draw mold assembly drawing, according to total drawings forming parts and all needs processing, and consider working drawing parts machining process of the part.