The traditional design process of modern power plant security system relies on discrete drawings, documents and manually identified data transfer, which has information silos, duplicate entries and consistency risks. This paper proposes a digital design collaboration framework based on standard metadata, by defining a unified metadata model, to open up the data barriers between product data, design tools, analysis software and operation and maintenance platforms in the whole life cycle of security system design. With metadata as the core carrier, the framework builds an automated data link covering equipment selection, design data management, security analysis, operation and maintenance configuration, realizing “one-time input, global reuse” of data.