A large amount of standard parts are usually used in manufacturing enterprises, in order to promote efficiency of product design, establishment of standard part library is very important. It can greatly reduce repetitive design and drafting. UG NX software is used as the platform. The method and step to establish the standard library based on UG/Open API and MoldWizard are studied deeply. The problems such as entry function and how to edit attributes of the standard library are solved eventually. By contrasted with other second development methods, MoldWizard is adopted to establish the enterprise’s standard part library. The design scheme and system architecture of the library are given, and the process of establishing the library is shown by examples. A mould for bottom telephone cover is rapidly designed based on MoldWizard. It proves that standard mould part library can help to improve the drafting efficiency and quality.