The phase group synchronization between any signals is further revealed,which is based on proposing the new concepts of the greatest common factor frequency,the least common multiple period,quantized phase shift resolution,equivalent phase comparison frequency and so on.Then the problem of phase comparison and processing between different frequency signals is solved and shown in detail.Using the basic principle and the variation law of group phase difference,the frequency stability better than 10-14/s can be easily obtained in the time&frequency measurement and control domain,and experimental results also show the phase relations between atomic energy level transition signal and the locked crystal oscillator signal in an active hydrogen atomic clock are strict phase group synchronization,and locked precision with 10-13/s can be reached based on phase group synchronization.The phase group synchronization can provide technical support to frequency linking among radio frequency,microwave and light frequency. The phase group synchronization between any signals is further revealed, which is based on proposing the new concepts of the greatest common factor frequency, the least common multiple frequency, quantized phase shift resolution, equivalent phase comparison frequency and so on. comparison and processing between different frequency signals is solved and shown in detail. Using the basic principle and the variation law of group phase difference, the frequency stability better than 10-14 / s can be easily obtained in the time & frequency measurement and control domain, and experimental results also show the phase relations between atomic energy level transition signal and the locked crystal oscillator signal in an active hydrogen atomic clock are strict phase group synchronization, and locked precision with 10-13 / s can be reached based on phase group synchronization. phase group synchronization can provide technical support to frequency linking among radio frequency, microwave and light frequency.