A microwave hydrolyzation-ion chromatography method for the determination of lentinan monosaccharide composition was established. Conditions of microwave hydrolysis of polysaccharide: the concentration of trifluoroacetic acid was 3.0 mol/L. The hydrolysis temperature was 130 ℃. The hydrolysis time was 30 min. The solid-liquid ratio was 20 mg polysaccharide sample/7 mL trifluoroacetic acid solution. Polysaccharide hydrolysate was performed on an CarboPac PA-20 ion exchange column, with a mobile phase consisting of 3.75 mmol/L NaOH solution at the flow rate of 0.5 mL/min. The detector was pulsed ampere electrochemical detector, and the column temperature was 30 ℃. Compared with the conventional hydrolyzation-PMP derivatization-liquid chromatography, the analysis time of each sample was reduced from 365 min to 65 min. Methodological study showed that the method has high accuracy, reproducibility and stability, and can be applied to the analysis of monosaccharide composition of lentinan. Through the analysis of 106 lentinan samples, an ion chromatographic fingerprint based on polysaccharide monosaccharide composition information was constructed, and 6 common characteristic peaks were determined, which were fucose, glucosamine, galactose, glucose, mannose and xylose, with the similarity was above 0.95. The establishment of the fingerprint provides a more comprehensive reference for the quality control of lentinan.