Intelligent communication technology has become a research hotspot with complex electromagnetic environment in electromagnetic field. It is of great significance to analyse essential radio mechanism and realize the spectrum sensing and modulation recognition tasks in complex environment. Focusing on basic and cutting-edge requirements of electronic information system under complex electromagnetic environment, we introduce research status of radio signal modulation recognition. On this foundation, we expound traditional and intelligent radio signal modulation recognition methods is with the development of electromagnetic characteristics respectively. Finally, we comprehensively summarize key technologies and look forward the development trend in this field.