The invention discloses a preservative-resistant bread yeast strain and a method for preparing bread yeast. The method comprises the following steps: screening the bread yeast on a solid culture medium containing 0.1 to 1 weight percent of preservative, selecting the yeast with large colony, preserving the yeast on a slant culture medium containing 0.1 to 1 weight percent of the preservative, inoculating the yeast on the slant culture medium to a liquid culture medium containing 0.1 to 1 weight percent of the preservative to be cultured, and inoculating the yeast to the liquid culture medium containing 0.5 to 1 weight percent of the preservative to be cultured; and repeating the steps more than once, and screening the yeast on the solid culture medium containing 0.1 to 1 weight percent ofthe preservative to obtain the preservative-resistant bread yeast strain. The invention also provides a method for preparing the preservative-resistant bread yeast. The preservative-resistant bread yeast strain and the bread yeast have the advantages that the preservative-resistant bread yeast strain and the bread yeast enhance fermenting activity of the bread yeast in the presence of the preservative, shorten fermenting time of dough, and improve production efficiency.