A communication system and a communication method for converging different access technologies are disclosed. The method includes: a convergence terminal accesses a network converging different access technologies, and transmits a traffic request message including a traffic identifier to a convergence access switch via an access network when the convergence terminal is required to perform traffic (201); the convergence access switch acquires an address of traffic server according to the traffic identifier in the received traffic request message, and forwards the traffic request message including the traffic identifier to the traffic server (202); and the traffic server performs information interaction with a Home Subscriber Server (HSS), and provides traffic through the network converging different access technologies when it is determined that the traffic server is able to provide the traffic to a user corresponding to the convergence terminal (203). With the system and the method of the disclosure, networks provided by various wireless mobile communication technologies can provide communication traffics cooperatively, thus improving user experience.