RP(Relying Party) downloads signed objects in RPKI(Resource Public Key Infrastructure) and processes those objects into authorised relations between IP addresses and AS(Autonomous System), which is used to guide the BGP routing. The current RP uses rsync to realize the synchronization, but rsync(Remote Sync) synchronization algorithm does not take the characteristics of the files (directorise) in the RPKI into account. So the synchronization is not efficient. Through the analysis and combining with the characteristics of the files (directories) in the RPKI, this paper designs and realizes a RPKI repository synchronization tool named htsync which is based on ordered hash tree. The experimental results show that, compared with rsync, htsync transmits less data and costs less time during synchronization. In three designed experimental scenario, average speedup ratios of synchronization time are 38.70%, 30.13% and 3.63%, effectively reduce the consumption of time and resources.