从理论上研究了双频激光混合泵浦掺饵光纤放大器（ＨＥＤＦＡ）的增益特性。着重分析了ＨＥＤＦＡ的阈值和饱和行为，证明它比一般单频激光场泵浦的掺饵光纤放大器具有更高饱和增益和更低的单光阈值等优点。实验结果支持了上述结论。 The gain characteristics of dual-frequency laser hybrid pumping doping optical fiber amplifier (HEDFA) are theoretically studied. The threshold and saturation behavior of HEDFA are analyzed, and it is proved that HEDFA has the advantages of higher saturation gain and lower single-light threshold than the conventional single-frequency laser-pumped piggy-fed optical fiber amplifier. The experimental results support the above conclusion.