The invention relates to rhizomucor miehei alpha-amylase, and an encoding gene and an application of the rhizomucor miehei alpha-amylase. A protein has alpha-amylase activity; the gene of the proteinis efficiently expressed in pichia pastoris; the maximum enzyme activity after high density fermentation of the pichia pastoris is 29794.2U/mL; the specific enzyme activity after purification is 3502.1U/mg; an optimum reaction pH (potential of hydrogen) is 6.0; the protein keeps stable when the pH is 4.5-8.0; an optimum reaction temperature is 75 DEG C; and the protein keeps the higher enzymic activity below 65 DEG C and has better thermal resistance. The amylase can increase a specific volume of steamed bread by 7.7% and retard aging of the steamed bread when the amylase is applied to the steamed bread; and a maltose content can reach 54.1% when the amylase is applied to maltose production. The amylase has good utilization potentiality in the food industry.