A communication method applicable to different scenarios of interworking between communications systems includes determining, by a session management network element, a first data channel in a first system, where the first data channel is a data channel to be synchronized with a terminal device; and synchronizing, by the session management network element in an interworking procedure for the terminal device from the first system to a second system, at least one of the first data channel or a second data channel that is in the second system and that corresponds to the first data channel.