A method, a device, and a system for realizing unified communication in the field of communication are provided, so as to solve the problems in the conventional art that a client can only initiate a call to a terminal instead of controlling the subsequent call and that no call association exists between the client and the terminal. A call control method of a softswitch equipment includes: sending a call identification and call state information to an application server, so that the application server sends the call identification and the call state information of the call to a client bound to a terminal; receiving a control request including the call identification and a control instruction and sent by the application server; and controlling the call corresponding to the call identification according to the control instruction in the control request. The present invention is applicable to the unified communication mode.