Embodiments of the present application provide a method and an apparatus for controlling a data replication transmission function of a terminal device. The invention can control a data replication transmission function between a cell group and a terminal device, and can avoid impacting on subsequent data transmissions when a transmission link is problematic. The method comprises: the terminal device suspending data transmissions on a first bearer when the data transmitted on the first bearer reaches the maximum number of retransmissions on a first radio link control (RLC) entity, the first bearer being a radio bearer for transmitting data in a data replication manner in a carrier aggregation (CA) scenario; and the terminal device reporting a radio link failure (RLF) message.