The utility model discloses a polarization feedback quantum key distribution system based on wavelength devision multiplex, include: the setting is at the quantum key distribution system transmittingterminal and the quantum key distribution system receiving terminal at built on stilts optic fibre both ends, quantum key distribution system transmitting terminal includes QKD transmitting terminal,polarization feedback signal transmitting terminal and wavelength devision multiplex device, quantum key distribution system receiving terminal includes QKD receiving terminal and polarization feedback signal receiving terminal, the transmitting terminal of QKD transmitting terminal, polarization feedback signal transmitting terminal is connected in the receiving terminal of wavelength devision multiplex device respectively, and the transmitting terminal of wavelength devision multiplex device passes through the optic fibre channel with polarization feedback signal receiving terminal to be connected, and the transmitting terminal and the receiving terminal of QKD receiving terminal of polarization feedback signal receiving terminal are connected. The utility model discloses an increase thewavelength devision multiplex device in quantum key distribution system transmitting terminal, pass through wavelength devision multiplex mode transmission signal and solely and the reference light,can prevent the mutual interference between reference light and the pilot light when the needs polarization feed back.