Acquiring high quality RNA is the basis of plant molecular biology research, plant genetics and other physiological investigations. At present, a large number of nucleotide isolation methods have been exploited or modified, such as commercial kits, CTAB, SDS methods and so on. Due to the nature of different plants, extraction methods vary. Moreover, efficiency of certain approach cannot be guaranteed due to composition of different plants and extracting high quality RNA from plants rich in polysaccharides and polyphenols are often difficult. The physical and chemical properties of polysaccharides which are similar to nucleic acids and other secondary metabolites will be coprecipitated with RNA irreversibly. Therefore, how to remove polysaccharides and other secondary metabolites during RNA extraction is the primary challenge. Dendrobium huoshanense is an Orchidaceae perennial herb that is rich in polysaccharides and other secondary metabolites. By using D. huoshanense as the subject, we improved the method originated from CHAN and made it suitable for plants containing high amount of polysaccharides and polyphenols. The extracted total RNA was clear and non-dispersive, with good integrity and no obvious contamination with DNA and other impurities. And it was also evaluated by gel electrophoresis, nucleic acid quantitative detector and PCR assessment. Thus, as a simple approach, it is suitable and efficient in RNA isolation for plants rich in polysaccharides and polyphenols.