Soils associated with different plantation types have different buffering capacities for acidification, and fungi play an important role in the soil system. However, there is lack of in-depth research on the relationship between soil fungal community structure and composition and soil acidification. In this paper, we investigated soil properties and fungal communities across five plantation types and different soil horizons in a severely acid-polluted site in Southwest China and evaluated the potential relationship between soil fungal community and soil acidification. Four plots were established in each of the five forest stands in Tieshanping, Chongqing, including pure stands of Pinus massoniana Lamb (Pi), Cinnamomum camphora (Linn) Presl (Ci), and Schima superba Gardn. et Champ (Sc), and the mixed stands of conifer and broadleaves (Pi_Ci and Pi_Sc, respectively). Soils from O and A horizon were collected in August 2018, and soil fungal community composition was characterized via high-throughput sequencing using the Illumina Miseq PE300 sequencing platform (Illumina, Inc., CA, USA). The results showed that (1) Ci significantly improved soil acidity with higher pH and lower NH₄:NO₃ compared to Pi and also increased total phosphorus (TP), while Sc significantly (P<0.05) increased soil NH₄:NO₃ and decreased TP and total potassium (TK). (2) Ci was characterized by significantly greater fungal diversity indicated by Chao 1, Sobs and ace; the fungal diversity in Pi_Sc was the lowest indicated by Shannon, Chao1 and Sobs; and soil pH and cation exchange capacity (CEC) were positively and NH₄:NO₃ was negatively correlated with fungal diversity (P<0.05). (3) Both forest types and soil horizons significantly affected soil fungal community structure (P=0.001), and the effect of forest types was greater than soil horizons. And soil fungal community was divided into two clusters by soil acidification indices (pH, CEC), including Ci and Pi_Ci; Pi, Sc and Pi_Sc. (4) More beneficial taxa (like Mortierella) were found in soils associated with Ci; and ectomycorrhizal fungi dominated in soils of Pi including Russulaceae, Russula, Tomentella and Sebacina; while in soils associated with Sc and Pi_Sc, greater abundant plant pathogen (Cladophialophora, Paecilomyces and Venturiales), acid-producing and acidophilic taxa (Paecilomyces, Penicillium) were detected. Fewer acid-producing and acidophilic taxa found in soils associated with C. camphora indicated that planting C. camphora might help soils recovery from acidification, while planting S. superba might not be beneficial. Our findings illustrate how differences in soil fungal communities may affect soil-acidification-buffering capacity across different forest types, which have important implications for understanding environmental functions within the context of microbial diversity.