With the development of fiber Bragg grating (FBG) and FBG based resonant cavity writing and signal demodulation technique, the measurement precision and frequency bandwidth of FBG sensor continue to be improved. It can highly promote its application in several fields of high precision detection requirements, such as geophysical exploration, seismic observation and marine observation. At present, the development of high-precision and wide bandwidth FBG sensors still face some challenges of key devices and techniques, including high-fineness FBG based resonant and low-noise narrow-linewidth tunable laser, high-precision broadband FBG wavelength demodulation technique, large-scale networking technique and high-sensitivity signal pickup probe design. Firstly, this paper introduces the development of high-precision FBG sensing technique. Secondly, it focuses on the cord devices and key techniques required for high-precision FBG sensing system and their applications in geophysical exploration, seismic observations and ocean observations. Finally, the high-precision FBG sensing technique and its application are prospected. In order to provide references for the development and application of high-precision fiber Bragg grating sensing technology, this paper aims to analyze and summarize some of the core techniques involved in high-precision FBG sensing technique and its application and the key issues that need to be solved.