In response to the high-precision time-frequency transmission requirements of optical fiber links, the high-precision two-way time-frequency transmission of the same fiber and the same wave is realized based on the method of mixed coding and co-transmission of time signal and frequency signal, and the effectiveness and output of IRIG-B codec module are verified. On the basis of reliability, a time synchronization accuracy of 1ns and a delay jitter of 17 ps are achieved. The experimental results show that the scheme proposed in this paper can effectively compensate the time delay and jitter caused by temperature changes in long-distance optical fiber time-frequency transmission.