The invention discloses a filtering method suitable for dendrobium officinale dry buds. The filtering method comprises the steps of crushing the dry buds, sieving the crushed dry buds through a sievewith meshes of 60-80, extracting the dry bud powder by a hot extraction method, adding 5-30 parts of sterile water precooled to the temperature of 1-7 DEG C for proper dilution, filtering with nylon filter cloth with meshes of 100-500; and filtering with a 25-0.22-micrometer absolute precision filter element under the condition of a refrigeration environment (at the temperature of 1-7 DEG C) to obtain the final product. According to the filtering method, a heat extraction method is adopted to control the filtering temperature so as to improve the yield and reduce loss of effective ingredients.