Quantum network communication system

The invention discloses a quantum network communication system, and relates to the technical field of quantum key distribution. An optical path reciprocating structure is formed by a quantum line terminal comprising a laser, a first optical circulator and an integrated coherent receiver, an optical splitter and a plurality of quantum network units comprising a phase modulator and a second optical circulator, so that a quantum state moves in circulation; information can be carried, and multi-user access to the quantum network based on the quantum network unit is supported through multi-band quantum state transmission and separation. The optical structure is simple, in the whole back-and-forth structure, the quantum line terminal generates an initial optical signal only through one laser, and one integrated coherent receiver receives an optical signal returned by a user; when a new user accesses, only one phase modulator and one optical circulator need to be inserted to form an optical path back-and-forth struc