Fiber-optic Fabry-Perot microcavity sensors have many advantages, such as antielectromagnetic interference, resistance to harsh environments, small size, and high accuracy. The measurement of physical parameters in high-temperature environments based on fiber-optic Fabry-Perot sensing technology has attracted wide attention from researchers. Based on the principle of fiber-optic Fabry-Perot interference, the principles of Fabry-Perot multibeam interference and beam coupling model, as well as two demodulation techniques for demodulation of interference spectrum signals were presented. In addition, the use of fiber-optic Fabry-Perot sensing technology in high-temperature environments was discussed. The research progress of physical parameter measurement based on the development trend of fiber-optic Fabry-Perot sensing in high-temperature environments toward miniaturization, batch preparation, and multipurpose due to the birth of new process manufacturing technology were analyzed as well.