Optical fiber Fabry-Perot sonic sensor signal demodulation system and method

The invention discloses an optical fiber Fabry-Perot sonic sensor signal demodulation system and method, and the method comprises the steps: firstly heating a Fabry-Perot cavity through a laser beam, enabling a cavity body of the Fabry-Perot cavity to be heated and deformed, adjusting an orthogonal working point (Q point) of a sensor to the center wavelength of the other signal detection laser, then, controlling the heating laser power in real time through a PID algorithm, keeping the position of an orthogonal working point of the sensor unchanged, and achieving high-sensitivity and high-stability detection signal output of the sensor. Measurement of physical quantities such as pressure, sound waves and ultrasonic waves in different application occasions can be met, the influence of changes of environmental factors such as temperature and pressure fluctuation on demodulation signal stability can be effectively reduced while demodulation precision is guaranteed, and the anti-interference capability of a sensin