【Objective】Soil nematodes are pivotal for soil health and highly sensitive to land-use changes. This study investigated the effect of artificial grassland construction on soil nematode community structures and energy flow in sandy soils of the Yellow River floodplain. 【Method】The experiment was conducted in June 2022 and 2023, examining nematode communities across four land use types: farmland (winter wheat-summer maize rotation), monoculture ryegrass (Lolium perenne), monoculture alfalfa (Medicago sativa.), and a mixed alfalfa-ryegrass artificial grassland. 【Result】Results showed that compared with farmland, the mixed artificial grassland significantly increased the total nematode abundance by 68.06%. Artificial grassland significantly reduced the relative abundance of bacterivores nematodes by 18.43%~21.11%, while increasing plant-parasitic nematodes by 133.80%~180.28%, leading to a more balanced trophic structure. Regarding ecological function, although artificial grassland did not significantly alter the maturity index, it increased the Structural Index and decreased the Basal Index, thereby enhancing the complexity and stability of the soil food web. Energy flow analysis revealed that artificial grassland, particularly the mixed-sowing system, significantly increased the total energy flux of the soil nematode food web through the plant-based pathway (plant-herbivore-omnivore/predators), reflecting intensified ecosystem carbon metabolism and energy flow. Notably, redundancy analysis identified soil microbial biomass carbon/nitrogen, dissolved organic carbon, available phosphorus, and capillary porosity as the primary environmental drivers of nematode community structure and function. Artificial grassland promoted the succession of nematode communities toward complex, stable states and enhanced energy flux through the synergistic improvement of labile C and N pools and amelioration of soil microenvironments. 【Conclusion】This study reveals that artificial grasslands construction effectively improves the structure and function of soil nematode communities and support higher energy flux through the nematode food web in the sandy soil of the Yellow River Floodplain. Mixed-sowing artificial grasslands demonstrate more significant ecological benefits due to greater plant functional diversity, providing important references for regional land management and ecological restoration.