An inter-base-station synchronization method and a device are provided. The method includes: sending, by a source base station, a request for time synchronization to a target base station, request for time synchronization; receiving, by the source base station, an acknowledgment message from the target base station; sending, by the source base station, a particular sequence to a target user terminal located in a particular area, so that the target user terminal sends the particular sequence; and detecting, by the source base station, the particular sequence, and performing time synchronization between the source base station and the target base station. According to the present disclosure, the user terminal located in the particular area forwards the particular sequence, so that to-be-synchronized base stations detect the particular sequence to implement inter-base-station time synchronization.