A session management method, device, and system, such that a terminal can access a local data network using a local user plane function (UPF) network element even when the terminal is out of a management area of a remote anchor session management function (SMF) network element. The method includes: receiving, by an intermediate session management network element, one or more local data network access identifiers (DNAIs); and determining, by the intermediate session management network element, a target DNAI based on current location information of a terminal and the one or more local DNAIs, where the target DNAI is used to select a local session management network element for the terminal.