Abstract:The control algorithm of atomic clock group has a direct impact on the stability of atomic clock group and accuracy ,a good atomic clock group control algorithm plays an important role in the system of atomic clock time keeping .In order to further improve the stability of the atomic clock, the clock difference prediction was used for the control of atomic clock prediction for the first time, which was called a precontrol algorithm, and combined with the hysteresis control algorithm, formed the composite control algorithm for the hydrogen atomic clock group, and validated it by the actual hydrogen atomic clock data. The experimental results show that the performance of the composite control algorithm is better than the current hysteresis control algorithm.