There are some data problems between digital twin application and nuclear power plant, such as complicated data interaction, diverse data sources, single way of open sharing of data assets, inconvenient access and use of data. To deeply exploit data value, simplify data integration and data asset exchange in the nuclear power digital twin domain, and enhance the digital twin data warehouse product system, a data asset management system can be constructed by integrating business rules specific to the nuclear power digital twin field. This system could create structured knowledge assets and achieve effective data asset management. This paper proposes a data asset management framework and key technologies based on the nuclear power industry Internet platform. It elaborates the implementation content and solutions encompassing the construction of digital twin data warehouses, data asset access and classification, data asset management, and data asset services. This comprehensive framework enables the analysis, mining, and management of digital twin data assets, playing an important role in the circulation and utilization of nuclear power data elements, and effectively promoting the value release of data assets in nuclear power enterprises.