Embodiments of the present invention provide a synchronization method, a base station, and user equipment. The method includes: completing, by an unlicensed-spectrum base station, preemption of a radio channel of an unlicensed spectrum at a first time point; determining, by the unlicensed-spectrum base station, a second time point, where the second time point is a subframe boundary at which the base station starts to send an effective subframe; intensively sending, by the unlicensed-spectrum base station, synchronization signals in a first time period between the first time point and the second time point, so that user equipment UE completes uplink synchronization in the first time period; and starting, by the base station, to send the effective subframe at the second time point.