The research progress and development status of spectral beam combining (SBC) using high-power fiber lasers is reviewed briefly, and a detailed introduction to the external factors that affect the beam quality is made. The influences of components in the SBC system and the linewidth broadening of the sub-light source array are mainly considered in the evaluation of beam quality. The summary of the existing theories and experimental results as well as the groundbreaking works for improving the beam quality of SBC in Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, is helpful to optimize the design of the built-in parameters of SBC and thus the further development of high-brightness SBC techniques is promoted.