Microfiber is a kind of novel fiber with diameter in the micrometer level, which aroused people's widespread attention in recent years. In this paper, first, sensing principle, guiding properties, and the calculation method of propagation constant of the microfiber are introduced, and the general expression used for estimating the sensitivity of interferometric microfiber sensor is summarized. Then, the common preparation methods of microfiber and typical interferometric microfiber sensors used in temperature, salinity and pressure sensing are introduced, such as microfiber ring resonator, microfiber directional coupler and microfiber coaxial Mach-Zehnder interferometer (MZI). Secondly, it focuses on the packaging method, environmental adaptability and response time of the microfiber coaxial MZI. Finally, the existing problems and the trend of future development of these sensors is summarized and prospected.