The ecological environment of sand-blown hilly area in northwest Shanxi is fragile and it is one of the most serious areas in China. This study investigated the community composition and niche change of herbaceous plants in artificial Caragana korshinskii forest in sandy-hilly region of northwest Shanxi Province. The natural herb community under artificial Caragana korshinskii forest with different planting years (CK, 6, 12, 18, 40, 50 a) was taken as the research object, and its community composition, important value and population niche change characteristics were analyzed. The results showed that:(1) A total of 52 species, 41 genera and 22 families were recorded in the composition of the natural herbaceous plants in the understory of Caragana korshinskii forest with different ages. In the early plantation period (0-6 a), the annual herbaceous plants were the dominant group, accompanied by a few perennial herbaceous plants (3 species). In the middle period (12-18 a), the understory herbaceous plants were mainly composed of perennial herbaceous plants (12 species), accompanied by annual herbaceous plants (6 species) and natural shrubs (2 species). In the later period (40-50 a), the understory vegetation was still dominated by perennial herbaceous plants (12 species). (2) Under Caragana korshinskii forest, the niche width and niche overlap of herbaces changed significantly. The dominant species in the early planting period (0-12 a) were the pioneer species (Artemisia dalai-lamaeand and Avena fatua), which had the widest niche width (9.46 and 9.34), and the largest niche overlap with other species (0.3 and 0.29). In the middle and late planting period (18-50 a), the dominant species changed into perennial herbaceous plants, and the niche overlap between Elymus dahuricus and other species was the largest (0.42), indicating that Elymus dahuricus was the dominant and generalized species in the understory plant community. (3) In the late planting period (50 a), most herbaceous plants mainly distributed in the center of the system clustering sequence diagram of niche overlap coefficient, indicating that herbaceous plants competed fiercely for resources in the same environment in the late planting period, and the understory herbaceous plant community was in the transition stage of succession. In conclusion, artificial planting of Caragana korshinskii forest is more effective to increase the diversity of herbaceous plant community than natural restoration (CK), but the competition of understory plant community for resources is more intense. These results have important reference value for vegetation restoration and ecological reconstruction in arid and semi-arid sandstorm areas, and have important significance for ecological restoration of artificial forest.