In view of the complexity of practical problems, the research status and technical challenges of blind source separation (BSS) in radar countermeasure applications are comprehensively analyzed. This paper summarizes and analyzes the research status of blind source separation in the field of radar signal sorting, radar anti-jamming and signal direction of arrival estimation in radar countermeasures, focusing on the theoretical and practical problems in the algorithm research and application. The results show that the research has a certain reference value for blind source separation, radar countermeasures and other fields.