A communication system includes a server for capability control, with a capability control file currently used by a corresponding device being provided in the server. The server includes a capability determination unit adapted to determine whether the summarization of the capabilities currently used by all the devices under the control of the server exceeds the capabilities limited by the capability control file; and a prohibition command sending unit adapted to send to the device a capability prohibition command corresponding to the capabilities. The device includes a capability prohibition unit adapted to prohibit the subsequent usage of the capabilities after receiving the prohibition command. A control method and a communication device are also provided.