Optical fiber strain coefficient automatic calibration method

The present invention discloses an optical fiber strain coefficient automatic calibration method. The method includes the following steps that: the length of an optical fiber strain region is inputted, a measured optical fiber is tensioned and is fixed between a first fixture and a second fixture according to a set distance; an optical fiber length and an optical fiber refractive index are inputted; a main control computer starts automatic calibration; a Brillouin optical time domain reflectometer is adopted to test optical fiber strain distribution so as to find out an optical fiber length corresponding to the optical fiber strain region; the Brillouin optical time domain reflectometer is adopted to test optical fiber strain distribution so as to find out an acting area length of the measured optical fiber; a calibration stepping distance is determined according to the acting area length of the measured optical fiber; the Brillouin optical time domain reflectometer is adopted to test optical fiber strain dis