Abstract: The target detection system based on non-cooperative radar illuminator is expected to be of high value in theoretical research and application. This paper introduces the concept and technical advantages of target detection system based on non-cooperative radar illuminator. Then, research status of this field at home and abroad in recent years is summarized. Compared with passive radar system using civil radiation source, the technical bottlenecks of target detection system based on non-cooperative radar illuminator in signal acquisition, processing, target detection and tracking are analyzed. This paper discusses the key technologies of system synchronization, direct wave suppression, non-cooperative target detection and target tracking.