Chinese yam, Coix chinensis Tod. and Euryale ferox were added to wheat flour, the effect of mixed powder with different addition amount on the gelatinization characteristics, thermomechanical properties of dough and texture characteristics of steamed bread were analyzed by using rapid viscosity analyzer, Mixolab hybrid experiment instrument and texture analyzer. The results showed that as the amount of mixed powder added increased. The gelatinization viscosity, disintegration value, retrogradation value, gelatinization temperature, gelatinization time, dough water absorption, formation time and stability time of wheat flour gradually decreased, and cooking stability and protein weakening gradually increased. The hardness and chewiness of steamed bread increased significantly (P < 0.05), and elasticity increased first and then decreased. The sensory evaluation was consistent with the results of the texture analyzer. When the added amount of mixed flour was 10%, the gelatinization properties of wheat flour were the best, and the quality of steamed bread was the best. The added amount of mixed powder, gelatinization properties, and dough thermomechanical properties were significantly related to the texture properties of steamed bread (P＜0.05). The texture properties of steamed bread could be predicted by the thermomechanical properties and gelatinization properties of the dough.