[Abstract] This topic is the main research rounded lid plastic mold design, this dome material is the ABS, ABS (propylene clear of styrene butadiene- commonly terpolymer) is used in industrial production of materials. Through to the plastic parts for process analysis and comparison, the final five is the design of board type mould structure. The subject from specific die structure design of the mould pouring system, the structure of its molding part, demoulding mechanism, cooling system, exhaust systems, the injection molding machine the choice of a detailed design. This topic is the main task of the design of the die casting die forming part of the system, the design of the structure, the structural design of the other in the standard series or experience data choice, finally complete set of mould design. Through the whole design process, and train our comprehensive consideration of the problems.