This article reports an optimization model of optical fiber time synchronization EDFA gain coefficient based on genetic algorithm (G A). According to a series of parameters such as the distance and attenuation of each section of optical fiber, the EDFA gain coefficient of each node is obtained for the purpose of maximizing the signal-to-noise ratio, SNR. This algorithm is further exploited for regulating the gains of bidirectional amplifiers, allowing optimization of the performance of the link. The developed algorithm was tested experimentally done with 210-and 300-km-long links in the laboratory, incorporating three and four amplifiers. The results suggest that, comparing with the fixed gain coefficient setting, the proposed solutions allow optimizing the SNR by 3-5 dB and reduce the phase jitter by about 20%.