An application method of Dendrobium candidum in preparing a medicine for treating hypertension, comprising : separately adding an adjuvant, according to a conventional medicine processing method, into Dendrobium candidum powder, or an extracting solution of Dendrobium candidum powder obtained by alcohol and water extraction, or a mixture of Dendrobium candidum powder and the extracting solution obtained by alcohol and water extraction, and preparing same as traditional Chinese medicine tablets, granules, suspended granules, pills, powder, or capsules, thereby obtaining a medicine for treating hypertension.