In order to study how to evaluate the dispersion of PVA fiber bundles uniformly, a variety of agitation and dispersion parameters were tested, and based on the theory of gray coexistence matrix, the dispersion evaluation method of PVA fiber was established. The dispersion effect of PVA fiber under different mixing factors, different stirring speed and different stirring blades was analyzed and the angular second moment of PVA fiber bundle and the entropy value of the line graph was plotted. The result shows that the dispersion of PVA fiber bundles can be evaluated by the method well, which provides a theoretical basis for the study of the dispersion uniformity of PVA fiber bundles.