Mold is the necessary process equipment for plastic molding production. In the past, mold design mainly depended on the experience of technicians. The mold processing and manufacturing largely depends on the operation skills of workers. Therefore, the low level of mold design, poor processing and quality, long production cycle, short service life and the renewal of new products will be disturbed by mold problems. With the continuous development of plastic molding technology, the importance of mold is increasingly recognized by people. Some even put forward the creed of "no mold, no product". In recent ten years, the plastic molding and processing industry at home and abroad has invested a lot of funds and research efforts in improving and improving mold design and manufacturing technology, and achieved many results, which can be summarized as follows: (1) Innovation of mold processing technology In order to improve the machining accuracy of molds and shorten the machining and manufacturing cycle of molds, the mold industry has widely used profiling processing, such as advanced technologies such as electrical machining and NC machining, as well as precision machining and measuring equipment such as coordinate boring, coordinate milling, coordinate grinding and CMM. (2) Various new die materials are widely used In the process of mold design and manufacturing, the selection of mold materials is a very important problem. Whether the material selection is reasonable or not will directly affect the processing cost, service life and the quality of plastic products. Many new die steels with good service performance, good processability and small heat treatment deformation have been developed, such as pre hardening steel, new quenching and tempering steel, maraging steel, precipitation hardening steel and corrosion-resistant steel. (3) The degree of standardized and specialized production of mold parts is higher and higher Mold processing is a typical one-piece and multi variety production. The standardization of mold parts and the specialized production of mold parts are one of the important methods to shorten the mold processing cycle and reduce the mold production cost. According to foreign statistics, after the specialized production of mold standard parts, the mold cost is reduced by 50%. Various industrial countries attach great importance to the standardization and specialization of mold parts. The degree of mold standardization in the United States and Japan has reached 70%, and the degree of specialized production is 90% and 70% respectively. The degree of standardization of domestic molds is only about 20%, and the specialized production has just started, but the relevant departments are strengthening this work. (4) The application of CAD / CAM technology is becoming more and more common At present, the research on plastic mold CAD / CAM technology is widely carried out at home and abroad, and many software systems have been developed, which have been applied in extrusion and injection molding. In terms of injection mold CAD / CAM technology, with the participation of people, the computer can automatically complete the process analysis of plastic products, the flow analysis and thermal analysis of plastic melt in the molding process, as well as various calculation, design and drawing of injection mold; The cam computer can control the NC machine tool to automatically complete the machining task of die parts; If CAD / CAM is integrated, the whole design, processing and manufacturing of injection mold can be completed automatically by computer with the participation of people. Injection mold CAD / CAM technology is widely used in industrial developed countries, and commercial system software is sold in the market. China has also carried out a lot of research and development work in this regard and achieved some results, but there is still a certain gap in the application and promotion of this technology compared with foreign countries, which needs to be further improved and improved.