dendrobium officinale is a kind of precious chinese herbal medicine. it is a perennial herb with bushy stems, cylindrical shape, 10-30 cm high and 3-8 mm thick. it is known as the "giant panda" in the field of "life-saving herbs" in the folk. because fresh dendrobium candidum is not suitable for preservation, because of its fresh and tender juice, easy to rot and deteriorate, especially in the mildew season, it is not easy to preserve, so in most traditional chinese medicine stores and hospital pharmacies, there are few fresh medicinal materials.