Optical fiber has the advantages of low loss, high stability, and strong anti-interference ability, which plays an outstanding role in the construction of long-distance, high-precision, and highly reliable time-frequency transmission system. This paper combs the implementation scheme and related research results of the long-distance optical fiber time-frequency transmission system, and analyzes the influence of bidirectional delay asymmetry and various noises on the transmission accuracy, stability, and transmission distance. In addition, this paper puts forward the next development research suggestion for the fusion of optical fiber time-frequency transmission network and existing optical fiber communication network.