The noise model of BTDM fiber-optic time transfer link is e stablished for the analysis of the main noise source and generation mechanism in fiber-optic time transfer system. The effects of RIN of laser,gain of amplifier and the number of amplifiers on the signal-to-noise ratio (SNR) of BTDM fiber-optic time tr ansfer system are studied.The results show that the received SNR of BTDM fiber-optic time transfer is the largest when the optical amplifier reaches the optimal gain,and the maximum SNR increases w ith the increase of the number of optical amplifiers and tends to be stable.In a certain range,the RIN of laser has more influence th e received SNR of BTDM fiber-optic time transfer link,and the bandwidth of receiver has smaller influence on the ji tter of the received signal in BTDM fiber-optic time transfer system when it is with the same length of fiber link but more optical amplifiers.The received SNR of BTDM fiber-optic time transfer decreases with th e increase of the laser d uration before timing signal and tends to the SNR of WDM -based scheme.