Anti-SOP scrambling OSNR detection method and anti-SOP scrambling OSNR detection system

The invention discloses an anti-SOP scrambling OSNR detection method and system, and the method comprises the steps: converting a signal of a transmitting end of an optical monitoring host A into a linear polarization state through a 0-degree polarization controller, dividing the signal into two beams through a coupler with a splitting ratio of gamma, measuring one beam through a power meter, recording the original power, enabling the other beam to enter an OPGN optical cable, and transmitting NT time, a signal collected by the A end and a signal received by the B end are combined through the polarization beam combiner at the B end of the optical monitoring host at the receiving end, then the electrically-controlled rotatable polarizer is controlled to traverse to the most ideal polarization angle and interference effect matched with the received signal, the minimum noise power is recorded, the power and the power recorded by the transmitting end are used, and finally the OSNR value is calculated. The method