In order to clarify the macroscopic deformation characteristics and microscopic structural characteristics of the remolded loess under humidification-dehumidification, the loess in a fill area in northern Shaanxi was taken as the research object. The WG single lever consolidation instrument and scanning electron microscope were used to humidify the remolded -Analysis of macroscopic mechanical properties and microscopic structural changes of soils under dehumidification conditions. The research results show that: in the macroscopic aspect, the lateral compressive strain is positively related to the number of humidification-dehumidification cycles, and the law of the lower limit compressive strain of the humidification-dehumidification cycle can be expressed by a power function, indicating that long-term water-soil interaction causes compaction Soil strength and bearing capacity decrease; microscopically, the humidification-dehumidification cycle increases the pore structure of the compacted loess, changes the particle shape from flat to round, and the particle contact mode changes from surface-to-surface contact to point-to-point contact , Resulting in loose soil structure cracks, friction between particles and bearing capacity reduced. The macroscopic and microscopic analysis of the remolded loess provides a theoretical basis for the construction of loess regions.