This application provides a communication method, an apparatus, and a system, to improve communication efficiency. One method includes: sending, by an access network node to a terminal device, indication information indicating to transmit a quality of service (QoS) flow by using a bearer, wherein a protocol stack corresponding to the bearer supports transmission of the QoS flow through a first path, wherein the first path passes through one of (1) a service data adaptation protocol (SDAP) layer of a master node and a protocol layer below an SDAP layer of a secondary node, or (2) an SDAP layer of the secondary node and a protocol layer below an SDAP layer of the master node; and transmitting, by the access network node, the QoS flow by using the first bearer.