Soil preferential flow is a common way of water flow in the soil, which causes soil water loss, groundwater pollution, and reduces slope soil stability. This paper takes a typical desert grassland as the research area in Yanchi County, Ningxia. And we selected artificially constructed shrubland (9, 14, 24, and 35 ages) as the research objects and used blank grassland as the control group, which explored the characteristics of soil preferential flow and its relationship with soil structure by soil water infiltration combining dyeing method, CT scanning method, and image processing technology. The results showed that:(1) there were significant differences in soil preferential flow characteristics and macroporosity. Soil macroporosity gradually and color depth of soil infiltration increased with the increase of planting years. Meanwhile, the ratio of dyeing area increased with the increase of Caragana korshinskii forest age. (2) The depth of soil matrix flow increased with the increase of vegetation planting years, and the soil priority degree of artificial Caragana korshinskii forest was significantly higher than that of grassland. (3) With the increase of the age of Caragana korshinskii plantation, the number of soil roots improved. The root activity in the process of shrub growth and development made the soil to have much lower tortuosity and stronger connectivity macropores, which were the main factors to lead to the preferential migration of soil water. Therefore, the changes of plant roots and soil macropores are the key factors to effect the soil water distribution in the process of artificial Caragana korshinskii restoration in desert steppe. The reasonable allocation of artificial forest plantation could improve soil water use efficiency in desert steppe effectively owing to its role in root system and soil structure characteristics modification.