The purification and enzymatic property of α-amylase produced by strain F21 were investigated. The α-amylase activity could reach 4 616.3 U/ml by the purification of salting-out and hydrophobic chromatography method. The study of enzymatic property showed that the optimum pH and temperature were 4.8 and 55 °C, respectively. The enzyme had higher stability under the conditions of pH 4.0-9.0 and temperature below 45 °C. Ca2+ had strong activation effect, and Fe2+ and Fe3+ had a strong inhibitory effect on enzyme activity.