Abstract: For the design and parameter optimization of licorice stalk forage processing equipment, this paper conducted experimental research on the bending characteristics, chemical component percentage content, and microstructure characteristics of licorice stalk with different diameters. According to the bending test, the maximum bending force of Glycyrrhiza glabra stalks with a moisture content of 13%～15% was 192.68 N, and the maximum bending strength was 539.62 MPa. As the diameter increased, the bending force gradually increased, but the bending stress gradually decreased, and the diameter had a significant effect on the bending force and bending stress（P＜0.05）. The percentage content of hemicellulose in licorice stalks determined by hydrochloric acid hydrolysis was 9.02%～10.71%, and the percentage content of cellulose and lignin determined by titration method was 23.37%～38.32%, 32.85%～40.3%. Using electron microscopes to observe the microstructure characteristics of licorice stalk, it was concluded that the licorice stalk was mainly composed of phloem, fiber, and pith. Using the grey relational theory, this paper established the correlation between the percentage content of licorice stem chemical components, the cross-sectional area size of each part of the microstructure, and the bending force, and obtained the percentage content of cellulose, hemicellulose, and lignin and the phloem, fiber, and pith. The correlation coefficients between the cross-sectional area and the maximum bending force were all greater than 0.5, indicating that the percentage of chemical components of the stem and the cross-sectional area of each part of the microstructure affected the maximum bending force of the licorice stem. This study can quantify the influence of various factors on the bending characteristics and provide a theoretical basis for the research on the "mechanical-stalk" interaction system and its processing tools.