Synchronous correction vulnerability detection method and device in quantum key distribution system

The invention discloses a synchronous correction vulnerability detection method and device in a quantum key distribution system, and the device comprises a wavelength division multiplexing module, a signal light delay module, a polarization detection module, and a classical information interception module, polarization used by the signal light in the synchronous correction process is detected, and therefore, whether to send an excitation signal to the signal light delay module to delay the signal light is selected according to the polarization information, whether to apply delay to the current signal light transmission is selected according to the received excitation signal, and the processed signal light is sent to a receiving end. According to the method, the base selection information published by the transmitting end and the receiving end is eavesdropped in the key distribution stage, and a detector can deduce a part of keys in combination with polarization information selected and delayed by the detector