Disclosed are a communication switching and establishing method and device. A switching procedure comprises: an access network device determining to switch from a D2N link to a D2D link; sending a switching command to a first terminal and a second terminal; receiving a switching complete response; and saving bearer information of a bearer, which needs to be switched to the D2D link, in the D2N link, or requesting to send a bearer keep request to a core network node. A communication establishing procedure comprises: after the access network device determines that communication needs to be established with the D2D link, determining whether a core network side link needs to be established for communication between the first terminal and the second terminal; if yes, sending a service request to a core network device, so that the core network device establishes a core network side link for the service request; and sending configuration information of the D2D link and establishment instruction information of the D2D link to the first terminal and/or the second terminal. The present application enables a first terminal and a second terminal to perform D2D communication, thereby enhancing network transmission efficiency.