The invention discloses an electric power asset heterogeneous data fusion method based on a knowledge graph. The method comprises the steps of firstly constructing a power asset knowledge graph model,extracting knowledge in the acquired power asset data through a power asset knowledge graph model then to achieve data fusion specifications, calculating relationships among the extracted knowledge entities by adopting a similarity comparison method based on named entity attribute relationships and an entity alignment algorithm, and performing multi-data-source knowledge fusion, the power asset data comprising structured data, semi-structured data and unstructured data. According to the design, comprehensive and accurate fusion of the multi-source heterogeneous data of the power assets is achieved, and good maintainability and expandability are achieved.