Soil aggregate structure is pivotal in regulating essential physical and biological processes within soil plant-microbe systems, thereby influencing various soil mechanisms. The alterations in aggregate pore structure during the transition from bare soil or weed-dominated degraded grasslands to artificial grasslands dominated by gramineous species remain unclear. To elucidate the impact of artificial grassland establishment on the pore structure of soil aggregates in degraded grasslands, this study selected natural alpine marsh meadows, degraded alpine marsh meadows, and artificially established meadows in Maqin County, Qinghai Province, as research subjects. Utilizing micro –CT technology, 3 –5 mm soil aggregates were scanned to obtain slice images with a resolution of 5.652 μm. These images were subjected to three-dimensional reconstruction and quantitative analysis using Avizo software and its plugins. The results demonstrated that, compared to degraded swamp meadows, soil organic carbon (SOC) in artificially established meadows increased by approximately 45.08%, yet remained lower than that of native alpine swamp meadows by about 26.37%. Porosity and macropores (>100 μm) increased by 22.03% and 2.81%, respectively. Regarding aggregate pore morphology, the establishment of artificial meadows led to increases in fractal dimension (FD), connectivity, and elongated pores by 2.66%, 1.18%, and 7.25%, respectively. During the degradation and restoration of alpine swamp meadows, SOC exhibited significant positive correlations with porosity, elongated pores, connectivity, and FD. In summary, the degradation of alpine swamp meadows severely disrupts the microstructure of soil aggregates, whereas the establishment of artificial meadows improves soil structure, rendering soil pore architecture more complex and thereby promoting the stabilization of soil ecosystems.