Embodiments of the present disclosure provide a data transmission method, terminal, and base station, relate to the communications field, and can improve data packet transmission efficiency. The data transmission method includes: receiving, by a terminal in an idle state, a first resource sent from a base station, where the first resource is used by the terminal to send an uplink application layer data packet to the base station; and sending, by the terminal, on the first resource, the uplink application layer data packet to the base station. The data transmission method is applied to the data transmission system.