Embodiments of the present invention provide a data packet transmission method and a device, which relate to the communications field, so as to reduce a storage burden on a base station in a data transmission process. The method includes: acquiring, by a base station that serves a UE, instruction information of a small data packet; and after receiving a radio resource control message sent from the UE, acquiring, by the base station that serves the UE, the small data packet from a core network device according to the instruction information of the small data packet, and sending the small data packet to the UE. The embodiments of the present invention are used for data packet transmission.