Abstract: The effects of adding Saccharomyces boulardii to fermented bran on the quality of dough and biscuit were studied, and the application value of probiotic fermented wheat bran in food was improved. The texture, specific volume change, antioxidant properties, sensory quality and volatile flavor substances of dough and biscuit made of fermented bran and low gluten powder were analyzed. The results showed that compared with the original bran (RWB) group, the elasticity and cohesiveness of the dough in the Saccharomyces boulardii fermented bran (SBWB) group were improved, and the brittleness, elasticity, resilience and chewability of the biscuits were improved, but there was no significant difference in specific volume. The antioxidant capacity of cookies in SBWB group was significantly increased (P＜0.05). The sensory score of SBWB group was higher than that of RWB group. Forty-four kinds of volatile flavor substances were detected by GC-MS, among which the relative content of alcohols and esters in the cookies of SBWB group was 3.31 times and 2.33 times of those in RWB group, respectively. compared with those of RWB group.The content of characteristic volatile flavor substances was mainly increased by phenyl ethanol, benzaldehyde, dimethyl adipate, 2-ethyl-5-methylpyrazine, etc. These flavourings were characterized by a bouquet of roses, fruit and nutty baking, giving the biscuits a rich flavor. In conclusion, the addition of fermented bran has a good effect on improving the quality of bran flour products.