Abstract: In the process of mold standardization planning and standard revision and revision, China has made extensive reference to the structure and technical content of ISO standards. Punching mold is one of the mould types which takes up a large proportion in the total amount of mould. Through the research on the current GB and ISO die standards, the size system has a great correlation with the priority number system. In particular, the size system of GB die frame standard basically adopts the priority number system, while other GB die parts standards and ISO basically adopt the priority number system of size system, but not completely in accordance with the value of the priority number system.Through the correlation study with the priority number system, the size system of China's current die standards can be roughly understood, and the degree of the new standards in the future bidding process, as well as whether the old standards need to be revised to provide a basis for judgment.