Objective To investigate the influence of different drying methods on the content of active ingredients polysaccharides and mannose in Dendrobium officinale, and to provide a scientific basis for the processing method of Dendrobium officinale. Methods Dendrobium officinale samples were dried by infrared drying, hot air drying, microwave drying, or vacuum freeze drying. Colorimetry was used to measure the content of polysaccharides, and high- performance liquid chromatography was used to measure the content of mannose. The influence of these drying methods on the content of polysaccharides and mannose was analyzed. Results There were significant differences in the content of polysaccharides and mannose between the Dendrobium officinale samples dried by these drying methods, and the Dendrobium officinale sample dried by vacuum freeze drying had significantly higher content of polysaccharides and mannose than the other samples (P<0.05). Conclusion The vacuum freeze drying method can preserve polysaccharides and mannose in Dendrobium officinale as much as possible.