Abstract: The link noise computing method of total noise weighted average has realized the 100% correction of link noises which have reciprocating fluctuation characteristics in theory.For link noises without such characteristics or those with extremely long fluctuation periods，the method cannot provide effective correction.Therefore，this method cannot be directly used to calculate the link noise of fiber optic time-frequency transfer link.But this method could be used for fiber optic time-frequency transfer link，if the initial phase difference，frequency difference，and frequency drift difference between the atomic clocks in different station had been calculated out by two-way satellite time-frequency transfer.Through simulation，reduce the calculation deviation of link noise to 0.1 ns，at least 6 atomic clocks are required.By increasing the number of atomic clocks involved in the calculation，this method can infinitely approach zero in calculation bias.

Key words: Fiber optic, Time transfer, Noise