A method and an apparatus for session reestablishment, an Access and Mobility Management Function entity AMF, a Session Management Function entity SMF and a terminal are provided. The method includes: AMF obtaining a Non-Access Stratum NAS message transmitted by a terminal, where the NAS message is to request to establish a new packet data unit PDU session connected to a same data network as an initial PDU session, and the NAS message carries first identification information of the initial PDU session and second identification information of the new PDU session assigned by the terminal; and transmitting a session management request to SMF corresponding to the first identification information. The session management request carries the first identification information and the second identification information, and the session management request is to cause the SMF to establish the new PDU session based on the first identification information and the second identification information.