The present disclosure discloses a method for implementing a Push to talk over Cellular (PoC) service and a PoC gateway so as to shorten the process for a terminal to implement a PoC service. The method includes: receiving a request from a first terminal for setup of a session with a second terminal; sending a registration request to an IP Multimedia Subsystem (IMS) core network after receiving the session setup request; receiving a registration success response from the IMS core and sending the session setup request to a PoC server, which forwards the request to the second terminal; receiving a session setup success response from the second terminal via the PoC server; and sending the session setup success response to the first terminal. The present disclosure also discloses a PoC gateway. With the present disclosure, the application of the PoC service will be wider.