In order to improve the stability of Benggang soil, prevent Benggang wall collapse, an experiment was conducted to study the crack evolution rules and shrinkage deformation rules of Benggang soil under the effect of Dry-Wet (D-W) cycles. A total of six D-W cycles were designed for the experiment, in which the four layers of soil were photographed at a fixed time and fixed site by using industrial cameras during the dehumidification process and in combination of digital image processing technology. Results showed as follows:(1) In the process of dehumidification, the sequence of soil morphology changes was:axial shrinkage, radial shrinkage, and crack development. (2) There was an obvious positive correlation between shrinkage cracking degree and liquid limit, plastic index and clay content. The maximum value of shrinkage cracking degree in the four layers of soil was 18.78% for the transition layer, and the minimum value was 5.41% for the sandy layer. The two soil layers were adjacent to each other on the section of the Benggang, and their great difference caused the terrible influence on the stability of Benggang. (3) As the D-W cycles, the radial shrinkage phenomenon no longer occurred. The rate of axial shrinkage, the rate of surface cracks, and the average width of the cracks gradually decreased. The total length of the cracks, the total number of crack strips, the number of crack intersections, and the number of lumps initially increased, then decreased, all parameters stabilized after the 3rd D-W cycles. Among the four soil layers, the transition layer was the most affected by D-W cycles, and the sandy layer was the smallest. These results could provide a scientific basis for the study on the mechanism of Benggang occurrence during the rain-evaporation cycles.