In order to solve the time-synchronization problem of distributed seismic data acquisition system, we designed a new high-precision time-synchronization technical system in this paper. In this system, a synchronous timing pulse was transmitted periodically during data communication. Through transmitting time measurement and its transmission delay time correction of synchronous timing pulse, high-precision multi-channel time synchronization was achieved in this technical system. And a time-synchronization technical system designed with high-speed programed chips was used to carry out the time-synchronous test. The result proves that the synchronous timing accuracy of time-synchronous system is better than 200 ns when the optical fiber is 2 km, which indicates that the time-synchronization system is stable and practical.