Different amount of buckwheat flour was mixed into wheat flour. The kneading property, the microstructure of the mixed flour dough and sensory quality of buckwheat steamed bread was studied. The results showed that, when the addition between 5%~15%, kneading dough time and peak area changed a little, the gluten network structure of protein in microstructure reduced a little, but when the addition to 20%, both kneading dough time and peak area reduced greatly, and the gluten network structure of protein in microstructure decreased obviously. Buckwheat steamed bread had the good quality when 15% buckwheat flour was added. So the buckwheat steamed bread had a good quality when the adding amount was 15% through comprehensive analysis.