The present invention relates to the field of communications technologies, and provides an inter-small cell handover method, a device, and a system. When UE is in a coverage hole of a serving small cell, the UE needs to perform synchronous measurement only on each available beam pair in a set of available small cells determined by the UE, thereby reducing a delay of re-accessing a high frequency network by the UE, and improving QoS of receiving a high frequency service by the UE. The inter-small cell handover method provided in embodiments of the present invention includes: performing, by UE, synchronous measurement, to determine a set of small cells available for the UE; sending the set of available small cells to a macro base station; when the UE is in a coverage hole of a current serving small cell, receiving, by the UE, a first synchronization indication sent by the macro base station; performing synchronous measurement according to the first synchronization indication, to select an available target beam pair; and handing over to a target small cell corresponding to the available target beam pair.