Disclosed are a quantum key distribution terminal and system. An optical transceiving device and an electronics media board in a quantum key distribution system are organically integrated into a whole through an electronics back panel. A quantum key distribution terminal with a compact structure and a high integration level is provided, so that uniform testing, maintenance and management for various components in the quantum key distribution system can be realized, thereby realizing the integration and terminalization of the key distribution system. The same quantum key distribution terminal can also be used to conduct flexible networking, thereby setting up a quantum key distribution system on a point to point, local area network or metropolitan area network scale.