High-power narrow-linewidth continuous-wave fiber lasers have a wide range of application values in scientific research, industrial processing, and military defense. On the premise of ensuring the output quality, continuously improving the output power is one of the key goals of high-power lasers. This research focuses on the suppression of the stimulated Brillouin scattering effect, which is one of the key factors restricting the laser power improvement. Various methods of nonlinear effect suppression and the corresponding performances are introduced, especially the spectral broadening method. In addition, the current problems and the development prospects of this technology are analyzed.