With the development of electronic countermeasure technology, the ability of electronic reconnaissance system to detect aircraft has been significantly improved.The existence of aircraft in modern air combat is seriously threatened and its penetration ability is greatly weakened.Radio Frequency (RF) stealth radar is a hot spot of research on aviation equipment at present.It can fundamentally improve the electronic defense capability of radar, and the research focuses on the waveform design of RF stealth radar.Firstly, the development of RF stealth radar is summarized, the advantages and disadvantages of four RF stealth technologies are compared, the main characteristics and technical indexes of electronic reconnaissance system are introduced, and the necessity and urgency of research on RF stealth radar are expounded.Then, three RF stealth waveform design methods based on composite signal, wide random variation of signal parameters and optimization algorithm are analyzed, and the difficulties and scientific exploration in waveform design are summarized.Finally, the development direction of RF stealth waveform design technology is predicted.