Entity disambiguation is a technology that maps named entities that appear in text to a known unambiguous structured knowledge base. Entity disambiguation is a key issue in natural language processing and plays an important role in the development of natural language. Entity disambiguation is of great significance to the application of knowledge graph construction, semantic search, knowledge question answering, recommendation system and so on. Based on the definition, classification and related research basis of entity disambiguation, a comprehensive analysis of entity disambiguation technology is carried out. Firstly, the five-tuple definition of entity disambiguation is explained, and the common classification and related research foundation of entity disambiguation are given. Then, the research content of entity disambiguation based on clustering and entity disambiguation based on entity link, and the research status is reviewed in detail. Finally, the application and evaluation of entity disambiguation are summarized, and the future research directions are summarized.