Power grid data asset management, maintaining the health and integrity of physical assets, optimising the allocation of physical assets, dynamically monitoring the distribution and operation of physical assets, and predicting the investment scale of operation and maintenance and technological transformation are important issues faced by power grid companies. First, the existing literature in this paper is sorted out to define the concept and characteristics of data assets. Then, a training model based on a knowledge graph and data asset relationship model is proposed. At the same time, the key technologies of the Industrial Internet of Things and the theoretical model framework of power grid technology are proposed, including device access, protocol conversion, edge data processing, connectivity, the first entry of data and the rapid growth of data volume. Finally, experiments are carried out to verify the framework proposed in this paper. Experiments show that the research on industrial Internet of Things and power grid technology based on knowledge graphs and data asset relationship model is of great significance for enterprises to exert data value and promote the development of the digital economy.