In the quantum communication network, quantum routers can store and forward quantum clusters with limited length. In the metropolitan area network(MAN) and wide area network(WAN), date volumes are very large, as a result, a large number of quantum clusters can not be stored and forwarded because of the length constraint problem and can only be transmitted in the form of quantum packets. In order to solve the above problem, a fragment transmission scheme of quantum cluster was proposed, it fragmented the quantum clusters, which were not able to be stored and forwarded by the quantum router, so that the fragmented quantum cluster could satisfy the storage and forwarding condition of routers and could be directly transmitted. The simulation results show that in the MAN and WAN, a large number of quantum clusters need to be fragmented because of the large amount of date, so compared with the existing data transmission scheme based on quantum cluster, the proposed fragment transmission scheme of quantum cluster can achieve the data transmission by consuming the short time and less quantum entanglement resources, and own the better practical value.