Multi-region optical fiber perimeter intrusion detection system and method

The invention discloses a multi-region optical fiber perimeter intrusion detection system, and relates to the field of optical fiber perimeter intrusion detection. A first optical fiber core transmits a pumping signal to a first junction box; the preset power of the pumping signal is divided into first preset power and second preset power through a second optical fiber coupler in the first junction box, and when the first preset power pumping signal is transmitted to the first optical fiber coupler through a second optical fiber arm, the wavelength of the first preset power pumping signal is set through a band-pass filter; the first erbium-doped optical fiber and the second erbium-doped optical fiber are pumped; the second preset power pumping signal is sequentially transmitted to each junction box through the first optical fiber core; in the pumping process, the optical power change of the reflected light signals is detected according to the reflected light signals generated by all the optical fiber environm