Abstract: Relying on knowledge graphs to analyze and assist decision-making on the vast information of power equipment has high value in practical engineering applications. To this end, analyze the relevant theories of knowledge extraction, knowledge fusion, and knowledge storage in the knowledge graph. A knowledge graph retrieval and analysis method based on subgraph matching was proposed, and the basic definition, division,execution, and result connection of subgraphs were elaborated in detail. A power standard retrieval and analysis model was constructed. Finally, taking tens of thousands of power data from a 500 kV substation in a certain power grid as an example, the retrieval results and characteristics of power big data under different retrieval methods were analyzed. The results fully verified the efficiency and accuracy of the retrieval model proposed in this paper.