Method and device for keeping base stations synchronous

The invention relates to a method and device for keeping base stations synchronous, wherein the method comprises the following steps: when base stations are already synchronous, recording magnitude of an adjustment value of each crystal oscillator adjustment within a preset period and corresponding current system time; according to the magnitude of the recorded adjustment value and the current system time, statistically analyzing change law of the adjustment values within the preset period to obtain a fluctuation cycle of the adjustment values and corresponding change ; when the base stations are out of synchronism, according to the fluctuation cycle of the adjustment values and the corresponding changes, periodically adjusting a crystal oscillator to keep synchronism. It is possible to keep the base stations synchronous in a long term, ensuring normal services within a cell and avoiding an island mode; by using a software implementation mode, it is possible to apply to a function of keeping all system base s