Abstract: With the popularity of 5G and the construction of base stations,higher requirements have been placed on the accuracy of time synchronization between base stations.At present,Precision Timing Protocol (PTP) can only reach tens of nanoseconds,and the frequency distribution effect is poor.When combined with SyncE technology,the frequency of all clocks on the network can be synchronized with the clock source.WR (White Rabbit) adds an all-digital dual-mixing phase detector(DDMTD)on the basis of PTP+SyncE can adjust and compensate the phase difference between nodes to eliminate the out-of-synchronization caused by the accumulation of phase noise for a long time,So as to realize the clock synchronization of the entire network node.This article introduces the principle and implementation process of the synchronization method combining SyncE and PTP、the WR synchronization method.At the end,an experimental platform is built,to verify the synchronization process.The test proves that the jitter of 100 picoseconds and tens of picoseconds can be achieved respectively,and the synchronization accuracy can reach the nanosecond and sub-nanosecond levels.