Crop lodging seriously affects crop production. The significant factors that affect crop lodging are stem shape, anatomical structure, and stalk physical properties. From a macro-mechanics point of view, the paper focuses on investigation of lodging resistance of millet stems and their correlated geometric parameters, such as stem length, section parameters (the long axis, short axis and area) and wall thickness; and biomechanical property indexes, such as cross-section, elastic modulus, flexural rigidity, and bending strength. In addition, the research also aims to develop a biomechanical evaluation method for (1) evaluation of lodging resistance of typical millet crops, such as DunGu, ChangZa, JinGu and ZhangZa, and (2) analysis of the correlation between the biomechanical property indexes mentioned above and stem lodging resistance of several high-quality millet crops. This research is expected to provide a new method to predict lodging resistance of millet stems based on their biomechanical properties for genetic selection of high quality millet crops.