This application provides a communication method and a related apparatus, which are applied to the multicast field, and in particular, relate to a multimedia broadcast multicast service MBMS. In this method, a terminal device receives, from a target base station to which the terminal device is handed over, at least one first data packet that is of a first service and that is sent in a transmission mode, and receives first indication information from the first base station. The terminal device sends a part of or all data packets in the at least one first data packet to an upper layer entity of the terminal device based on the first indication information.