A network communication system comprises a cloud network and at least one physical machine. The cloud network comprises at least one physical switch. Each the physical machine comprises a plurality of virtual machines and a virtual switch. Each of the virtual machines is connected to the at least one physical switch in the cloud network through the virtual switch. The virtual switch encapsulates a destination machine address of an egress frame sent by the virtual machines, attaches a destination switch address to the egress frame to be forwarded to the at least one physical switch, and receives and analyzes an ingress frame obtained from the at least one physical switch, so as to convert the destination switch address of the ingress frame to the destination machine address, for forwarding the ingress frame to one of the virtual machines.