Large-scale dumps are a common feature during the open-pit coal mining process in Inner Mongolia. Poor soil quality, coupled with harsh climatic conditions, makes the restoration of vegetation on the dumps extremely difficult. This poses a serious threat to the sustainable economic development of the region. Soil fungi play a crucial role in promoting plant growth and enhancing stress resistance through processes such as organic matter decomposition and nutrient cycling. Accordingly, this study examines the rhizosphere soil fungi of restored Gramineae, Leguminosae, and Forbs in five large open-pit coal mine dumps in Tongliao and Xilinhot, Inner Mongolia, analyzing their diversity, community composition, fungal functional types, network structure characteristics, and influencing factors to elucidate the adaptation patterns of plant rhizosphere soil fungal communities during ecological restoration. The results show that: (1) The Shannon and Simpson diversity indices of rhizosphere soil fungi in the Gramineae family significantly exceed those in the Leguminosae and Forbs. The dominant fungal communities of the three functional groups include Gramineae, Leguminosae and Forbs, belong to the phylum Ascomycota, accounting for 59.47% to 79.61% of the total abundance. There are significant differences in the relative abundance of the phylum Glomeromycota, with the highest in Leguminosae, followed by Gramineae, both of which are significantly higher than in Forbs. (2) The relative abundance of arbuscular mycorrhizal fungi (AMF) and soil saprotroph fungi significantly varies among the three functional groups, following a pattern of Gramineae>Leguminosae>Forbs, with the Gramineae family being significantly higher than Forbs. (3) The co-occurrence network of Gramineae rhizosphere fungi has the highest proportion of negative correlations and modularity index among the three functional groups. Compared to Leguminosae and Forbs, the network structure of Gramineae is more stable and has a wider ecological niche. The number of keystones in the network follows the order Gramineae>Leguminosae>Forbs. (4) 53.2%, 50.9%, and 16.2% of keystones of Gramineae, Leguminosae, and Forbs, respectively, were significant correlations with soil NH⁺₄-N, NO^-₃-N, and C/N ratio. In summary, compared with Leguminosae and Forbs, the rhizosphere soil fungi of Gramineae plants exhibit high arbuscular mycorrhizal fungi (AMF) abundance and high network stability. This indicates that Gramineae species are more suitable for the restoration of vegetation soil in dumps. The research findings can provide a theoretical basis for the restoration of vegetation and species selection in dumps.