Fiber-optic frequency transfer systems enable high-precision transmission of frequency signals.However,in long-distance frequency transmission,the signal optical power is constantly lost,which needs to be compensated by using an optical amplifier.Based on the good performance of two-stage amplifier,a two-stage bidirectional erbium-doped fiber amplifier (Dual-stage Bi-EDFA) that can be used for fiber-optic frequency transfer is designed,and the scheme is experimented and analysed.The results show that the measured gain of the scheme is up to 27.5dB,the noise figure is 3.56dB,and the gain flatness is less than 0.3dB.The scheme is applied to a 160km frequency transfer system with 1.09×10-14@1s and 2.36×10-17@10000s frequency transmission stability.