The white light interference type Fabry-Perot sensing technology can achieve absolute measurement of gap value. Research work in the field of fiber optic Fabry-Perot sensing technology based on white light interference is reviewed, research status of fiber optic Fabry-Perot sensor and its demodulation technology under extreme environments of high temperature and high pressure are focused on. The purpose is to analyze the principle and method of physical parameter measurement based on optical fiber Fabry-Perot sensing technology under high temperature and high pressure environment, and realize the practicality and engineering of optical fiber Fabry-Perot sensing technology based on white light interference.