Disclosed is an application method of radix paeoniae alba and dendrobium officinale for preparing a drug for treatment of hypertension, comprising : grinding radix paeoniae alba into powder and performing alcohol extraction, carrying out water extraction on the residue after alcohol extraction, and merging the concentrated extraction solutions; and grinding the dendrobium officinale into powder, adding the merged extraction solutions, and adding auxiliary materials to prepare a drug for treatment of hypertension. According to the present invention, the drug prepared by adding dendrobium officinale into extracts of radix paeoniae alba which is subjected to the alcohol-water extraction method has prominent effect in treating hypertension, and the antihypertensive effect of the drug is superior to that of western medicine irbesartan. Compared with the conventional water extraction, the alcohol-water extraction method of radix paeoniae alba reduces component loss, so as to improve the effectiveness, which promotes the complete utilization of the radix paeoniae alba by the human body in a process of oral medication, and the curative effect is improved. The drug has a selective adjustment function on people with high blood pressure and do not influence normal blood pressure.