Useful knowledge can be extracted from equipment fault diagnosis data for construction of a knowledge graph, which can effectively manage complex equipment fault diagnosis information in the form of triples (entity, relationship, entity). This enables the rapid diagnosis of equipment faults. Firstly, the related concepts of knowledge graph for equipment fault diagnosis were introduced, and the framework of knowledge graph for equipment fault diagnosis domain was analyzed. Secondly, the research status at home and abroad about several key technologies, such as knowledge extraction, knowledge fusion and knowledge reasoning for equipment fault diagnosis knowledge graph, was summarized. Finally, the applications of knowledge graph in equipment fault diagnosis were summarized, some shortcomings and challenges in the construction of knowledge graph in this field were proposed, and some new ideas were provided for the field of equipment fault diagnosis in the future.