High-power ytterbium-doped fiber lasers have important application value in precision processing, national defense, scientific research and other fields, but with the increase of power, the nonlinear effects inside the fiber begins to become prominent. Here, the generation process of nonlinear effects such as stimulated Brillouin scattering (SBS), stimulated Raman scattering (SRS), nonlinear refractive index, and transverse mode instability (TMI) is analyzed in detail, and suppression methods are proposed. In addition, from the perspectives of fiber oscillator and main oscillation power amplifier, the research progress of scholars in recent years on the basis of suppressing nonlinear effects to continuously improve the output power of ytterbium fiber lasers is briefly described. At present, the output power of the ytterbium-doped oscillator with all-fiber structure reaches 8kW; The output power of the single-fiber main oscillation power amplifier laser system has exceeded 20kW.