Due to the signal of global navigation satellite system is vulnerable, under the environmental shielding or electromagnetic interference, the availability and serviceability of global navigation satellite system with more uncertainty. In the domain of finance, communication, navigation and aviation, the stable, reliable and accurate time information is significant. Providing the backup time service with developing the Loran system, which have the superior cost-effective ratio. But the time service is not satisfied the application requirements due to its low accuracy. This article introduced that using the existing RBN station to transmit the differential information, which is effectively improved the time service accuracy of the Loran system, and this provides the basic guarantee for the livelihood and military timing requirements under the condition of satellite refusal.