The invention provides a communication method, device and system for a cloud network. The method comprises the following steps: an SDN controller receives a communication path request message sent by a strategic management device, wherein the communication path request message carries the address information of different communication nodes in communication with the strategic management device and the bandwidth requirement information and QoS requirement information of communication paths; according to the address information of the different communication nodes and the bandwidth requirement information and QoS requirement information of the communication paths, the SDN controller allocates communication paths meeting bandwidth requirements and QoS requirements to the nodes on both communication sides from network resources managed by the SDN controller; the SDN controller sends a message carrying the communication paths to bearer network forwarding equipment, so as to build communication paths among different communication nodes through the forwarding equipment. The technical scheme can guarantee the QoS requirements of communication, avoids waste of physical link resources on a bearer network and improves the network operation efficiency and the resource utilization rate.