进行了原状黄土的三轴剪切试验过程中的CT扫描,结合CT图像、数据与软化型应力 应变曲线的特点,对比分析土样的微观结构变化,认为由于围压没有超过结构强度的临界值,破坏表现为软化开裂破坏,是由轴向压密损伤为主导向横向开裂损伤为主导的转变过程;裂缝首先在结构强度较低的低密软弱大孔隙区域形成,随后衍生出一系列小裂缝,最终形成剪切面. The CT scanning in the process of triaxial shear test of intact loess was carried out. The microstructural changes of soil samples were compared with CT images, data and softened stress-strain curves. It is concluded that the confining pressure does not exceed the critical value of structural strength , And the failure manifests as the softening and cracking failure, which is mainly caused by the axial compaction damage and the transverse cracking damage. The fractures are firstly formed in the low-density and weak macropores with low structural strength, and then a series of small cracks , Eventually forming a shear plane.