The present invention discloses a clock synchronization method and device. The method comprises: receiving pulse signals continuously sent by a center plate card from zero time through taking a preset duration as an interval, wherein when a first pulse signal is received, the corresponding time value of the center plate card is equal to the value of the preset duration; performing statistics and recording of sequence numbers of the continuously sent pulse signals; and according to the sequence numbers and the preset duration, correcting the clock of a plate card to be synchronized to allow the clock of the plate card to be synchronized to synchronize the clock of the center plate card. The clock synchronization method and device improve the clock synchronization precision level of a missile and a carried rocket control system device so as to improve the test performance of the system.