In this study, a combination of indoor culture and high-throughput sequencing was used to analyze changes in nutrients and fungal communities in black soil after the addition of biomass charcoal. The following conclusions were drawn: 1) After six months of constant temperature, black soils containing biomass carbon changed in physicochemical properties. For example, soil pH, organic matter, water content, available phosphorus, and available potassium increased compared with CK treatment (P<0.05). 2) It was observed from high-throughput sequencing that the fungal diversity of black soil also changed. High-throughput sequencing detected five fungal phyla, including Ascomycota, Basidiomycota, Chytridiomycota, Zygomycota, and Aspergillus (Glomeromycota), in which Ascomycota was the predominant group of fungi, which accounted for about 70.6% of the total number of OTUs. The sequencing also detected 67 known genera, among which the dominant genus included the genus Geomyces and sickle Fusarium, Chaetomium, Penicillium, Humicola. The analysis of fungal diversity concluded that the abundance and diversity of fungi in the black soil after adding biomass carbon increased. In the redundancy analysis (RDA), environmental factors had a great influence on the abundance and community composition of fungi. Therefore, adding biomass carbon could not only improve the soil nutrients but also were significant in maintaining the diversity of soil fungal communities.