The invention provides a preparation method of a highland barley bran beverage and relates to the technical field of highland barley processing. The method comprises the following steps: preliminary treatment, crushing, microwave wall breaking, three times of extraction of deionized water, centrifugal separation, filtration, precipitation, sterilization, filling and the like. The method has the benefits that: the beverage prepared with the method is rich in multiple nutrients such as dietary fiber, glucan, vitamins and the like; only deionized water is used for extraction, no any organic solvent or acid base reagent is used, the extraction is natural, and no harmful substances are remained; meanwhile, an extraction method is environmentally friendly, and no waste water, waste gas or otherharmful substances are discharged to pollute the environment; by using the highland barley bran as a raw material to prepared the beverage, local resource advantages can be translated into economic advantages, income of farmers and herdsmen is increased, the highland barley bran is turned into treasure, and the comprehensive utilization of highland barley resources is realized; the process is simple, the industrialization is easy to achieve, and the price of raw materials is low. As a result, the production cost is low, and the beverage has better market competitiveness.