多波长放大是能够有效抑制窄线宽光纤放大器中受激布里渊散射(SBS)效应的一种新方法。对其基本理论进行了详细的介绍，并按照波长间隔的不同将其分为大波长间隔和小波长间隔多波长放大两种类型。综述了这两类多波长放大方法在理论研究和实验研究方面取得的重要成果，分析了它们各自在抑制SBS上的优势，指出大波长间隔多波长放大在提高单频激光输出功率方面具有明显优势，而小波长间隔多波长放大在进一步提升高功率光纤激光相干合成系统功率方面具有巨大的应用价值。

Multi-tone amplification is a novel technique to effectively suppress stimulated Brillouin scattering (SBS) effect in narrow-linewidth fiber amplifiers. The corresponding basic principles are described in detail. Multi-tone amplifications can be classified into large and small wavelength separation amplifications. Important outcomes in theoretical and experimental researches of these two kinds of amplifications are overviewed and their superiorities in SBS suppression are analyzed. It is pointed out that the large wavelength separation amplification shows great advantage in enhancing the output power of the single frequency laser and the small wavelength separation amplification is of great value to further enhance the output power of current high power coherent beam combination system of fiber lasers.