Abstract: High-precision time and frequency system is used as the basis for modern warfare to achieve precision strike, and the punctuality is considered to be the foundation and core of the high-precision time and frequency system. With the development of satellite positioning and timing system, by using the standard time signal remote transmission in the local acquisition of high precision time is used as a cheaper and convenient method. The time synchronization method and a kind of high precision time synchronization and time-keeping system are researched in this paper. The test results show that the system has good application effects, and it can be widely used at the time of communication, electric power, traffics , computer network synchronization and other fields.

Key words: Time-frequency system, Time synchronization, Time-keeping