Soil fungal communities are reconstructed under heavy metal stress. This study was conducted to explore the structural and functional diversity of soil fungal communities under different land-use patterns, namely grassland and farmland, in 15-year-old or 10-year-old poplar plantations ( cv. ‘zhonghuahongye’) near the Shibahe copper tailing dam and the surrounding area, located in Yuanqu County, Shanxi. The results indicated that the abundance and diversity of fungal communities were the highest in the 15-year-old poplar plantation and lowest in the grassland on the tailing dam. The dominant fungal groups in the study area were Ascomycota, Basidiomycota, and Mortierellomycota. The Ascomycota members were the most abundant at all four sampling sites, reaching 92.92% of the fungal community in the grassland on the tailing dam. The highest functional diversity of carbon utilization was found in the soil fungal communities of the 15-year-old poplar plantations; moreover, the diversity in the grassland on the tailing dam was significantly higher than that in the farmland and in the 10-year-old poplar plantation. Meanwhile, we also observed the highest glucoside carbon source utilization efficiency in the grassland. Notably, the correlation analysis revealed that Ascomycota was significantly correlated with the utilization efficiency of the glucoside carbon source in our study area. Moreover, the soil total nitrogen content, but not the soil heavy metal content, was significantly correlated with the abundance of the soil fungal community. There were significant correlations between the cadmium and arsenic contents and the soil fungal community diversity indices. Our results indicated that the soil fungal communities were more influenced by soil fertility and land use than by the soil heavy metal content. This study underlies the application of soil fungal communities in soil remediation of heavy metal-contaminated areas.