Embodiments of this application provide a packet transmission method, and a communications apparatus and system. The method includes: generating a packet based on address information of forwarding nodes on a packet forwarding path, where the packet includes a first indication field, the first indication field is used to indicate a compressed first element and a compressed second element, the first element and the second element are address information of different forwarding nodes, and different address compression manners are used for the first element and the second element; and sending the packet.