LEO-LEO microwave occultation measurement technique uses the frequencies near the water vapor absorption line to measure both refraction and absorption of the signals, enabling simultaneous retrieval of the temperature and water vapor profiles without an auxiliary background field, which overcomes the "temperature-humidity ambiguity" problem of GNSS-LEO radio occultation technique in the middle and low troposphere. At present, there is no any LEO-LEO occultation exploration mission in the space. In order to promote of LEO-LEO occultation measurement technique, the research frontiers and progress of temperature and water vapor profile detected by LEO-LEO microwave occultation are reviewed and summarized in this paper. Firstly, the development history of LEO-LEO occultation measurement technique is introduced, and the basic principle of LEO-LEO occultation detection and the frequencies selection are explained. Secondly, the research trends of retrieval technique of LEO-LEO microwave occultation detection temperature and water vapor profiles is emphasized, and the progress of LEO-LEO occultation missions is introduced. Finally the paper summarizes and offers a prospect. This study can provide basic scientific and theoretical reference for the realization of LEO-LEO occultation space exploration mission.