Preparation method of mountain rice flour

The invention discloses a preparation method of mountain rice flour. The preparation method is improved in two aspects of raw material culture and processing. Mountain rice cultivated in soil with a special proportion is used as a raw material, enzymolysis is cooperatively carried out on fibers, saccharides and the like in a brown rice germination stage by a mixed enzyme solution consisting of cellulase, xylanase, amylase and maltase, and a part of the enzymolysis substance is taken as nutrients for germination of mountain brown rice. The nutritional ingredients of germinated mountain brown rice are improved, gelatinization of rice flour in low-temperature and even cold drinking water is promoted, the content of gama-aminobutyric acid (GABA) in the germinated mountain brown rice is increased, and the content of coarse fibers, sugar and the like in the mountain brown rice is reduced. Nano mountain rice flour is obtained by cooperatively carrying out freeze-drying coarse crushing, short-time ultrahigh-pressure