Embodiments of the present disclosure disclose a session management method and an apparatus. The technology is specifically related to sending, by user equipment, a NAS message to an AGF, where the NAS message includes a PDU session establishment request message used to request to establish a PDU session, receiving, by the user equipment, a PDU session establishment accept message returned by a network side device, and establishing, by the user equipment, an access session with the AGF, where the access session is an access session related to the PDU session. The user equipment sends the NAS message to establish the PDU session, and establishes the access session with the AGF. Because the access session is related to the PDU session, the user equipment can map the PDU session to the access session, so that the user equipment accesses a 5G CN through a fixed network.