Abstract:To solve the problems of difficult molding，high hardness，easily broken strips，and rough taste of highly added buckwheat dried noodles，this study treated three kinds of buckwheat bran with different particle sizes by microwave，steam，and ultrasound. The buckwheat bran，buckwheat core flour，and wheat flour were mixed in a 15 ∶45 ∶40 mass ratio to make doughs and buckwheat dried noodles with a high buckwheat addition（60%）. The effects of buckwheat bran particle sizes and pretreatment methods on the thermomechanical properties of flour dough and the quality of buckwheat dried noodles were investigated. The results showed that different buckwheat bran particle sizes and pretreatment methods had different effects on the rheological properties of the dough mix and the quality of the buckwheat noodles. In the untreated group，the reduction in particle size increased the specific surface area of the bran，increased the stable time of the dough，and reduced the protein weakening degree of the dough.Meanwhile，the mechanical properties and cooking loss rate of dried noodles increased at first and then decreased，and the optimum cooking time，water absorption，hardness，chewiness，and tensile properties of dried noodles were significantly increased.After pretreatments，the protein weakening degree of the dough and the cooking quality and texture characteristics of the dried noodles were further improved. Pretreatments effectively reduced the hardness of the dried noodles，with ultrasonic pretreatment being the most effective in improving the hardness of the dried noodles. Moreover，microwave pretreatment of bran with medium particle size had the most significant effect on the mechanical properties and cooking quality of the dried noodles.In summary，it was an effective way to improve the processing performance of bran by selecting the appropriate particle size for proper pretreatment.