In order to explore the characteristics of extracellular proteases from large edible and medicinal fungi， proteases were isolated and purified from corn gliadin fermented by Armillaria mellea and purified by saturated ammonium sulfate precipitation crude enzyme solution， DEAE Sepharose Fast Flow anion chromatography column and Sephadex G-50 chromatography column. The results showed that the molecular weight of the protease was 18.4 ku， the optimum temperature of the protease was 60 ℃， it had good stability at 40-60 ℃， the enzyme activity was the highest when the pH value was 8， the stability range of pH was 6-8； Mn2+ could obviously promote the enzyme， ethylenediamine tetraacetic acid (EDTA) could obviously inhibit the neutral protease， and the Michaelis constant Km was 3.786 mg/mL. The results provided a theoretical basis for the research and application of proteases derived from large edible and medicinal fungi， and put forward new ideas for the research and development of enzyme preparations from large fungi.