A group communications method and system, and a device are provided. The method includes: when a first terminal initiates access to a local area network group, obtaining, by a group management function network element, an identifier of a first user plane network element to be accessed by the first terminal, context information of the local area network group, and a first session port identifier; creating, for the local area network group, a rule group applied to a first session port, and creating or updating, for the local area network group based on the context information, a local area network group forwarding action rule (FAR) applied to the first user plane network element; and sending a first message to a session management network element, for configuring the rule group on the first session port, and configuring the local area network group FAR on the first user plane network element.