To quickly analyze and judge the mechanical state of soil and solve practical engineering problems, the soil was looked as a special complex system in the paper and the analysis method of soil structure state was proposed based on the intrinsic relationship between the structure and state. The paper analyzed engineering mechanics state of the soil and predicted the mechanical behavior of soil engineering based on characteristics of the engineering condition and its impact on soil micro-structure. The soil mechanics teaching program was designed by three modules, which are the analysis of structure-state, teaching organization, and engineering problem analysis. The practice of the teaching program was carried out in Guizhou red clay teaching and achieved a good teaching effect.