土结构是一种物质状态，可以层次式的概念模型加以确定。从图象处理角度，提出了微结构定量研究的技术路线，确定了结构要素的量化方法。通过分形结构分析，探讨了天然结构和压力对黄土湿陷性的影响、水与土样之间的作用规律及其湿陷效应，提出了分形结构的湿陷性控制机理。 Soil structure is a kind of material state, which can be determined by the hierarchical conceptual model. From the perspective of image processing, the technical route of quantitative study of microstructure is proposed, and the quantification method of structural elements is determined. Based on the analysis of fractal structure, the effect of natural structure and pressure on the collapsibility of loess, the law of action between water and soil and its collapsible effect were discussed, and the collapsible control mechanism of fractal structure was proposed.