In order to explore the distribution pattern and its environmental driving mechanism of Sphagnum palustre L. community in Sphagnum Wetland of Qizimei Mountain, and further to provide scientific theoretical basis for the protection, restoration and utilization of Sphagnum wetland in subtropical mountain regions, field investigation and sampling for vegetation and environmental factors were conducted on June 2021 using standard sample method, followed by measurement and analysis of these samples. Subsequently, systematic clustering was used in quantitative classification of S. palustre communities; one-way ANOVA, multiple regression analysis and Pearson correlation analysis were used to test the differences in each of the environmental indicators, each of the physiological and growth indicators of S. palustre among the four clusters, as well as to test their pairwise correlation, which ultimately to elucidate the main environmental factors affecting S. palustre growth and its underlying mechanism. Results showed that: (1) A total of 37 field samples were divided into four associations: Ⅰ. Ass. Pteridium aquilinum-Sphagnum palustre; Ⅱ. Ass. Carex rubrobrunnea var. taliensis-Sphagnum palustre;Ⅲ. Ass. Juncus setchuensis+Cnidium monnieri -Sphagnum palustre; Ⅳ. Ass. Hosta ventricose+Lycopus cavaleriei-Sphagnum palustre. (2) Each of the four growth indicators (height, number of capitula, coverage, and biomass) of S. palustre showed gradual decreasing trend from Ass. I to Ass. Ⅳ. Each of the nine physiological indicators (TN, TP, TK, TC, C/N, C/P, N/P, N/K, and water content) in S. palustre tissue showed significant differences among the four associations; among which, tissue water content and N/K in S. palustre exhibited increasing trend from Ass. I to Ass. Ⅳ, with highest values occurred in Ass. Ⅳ.（3）Multiple linear regression analysis showed that water table and soil N/K were principal environmental factors affecting growth and distribution of S. palustre populations in Qizimei Mountain. In this study, excessive water content in S. palustre tissue caused by prolonged flooding stress inhibited its photosynthesis, which further impede the growth. On the other hand, high N load led to S. palustre growth was limited by K, resulting in unbalanced nutrient absorption and thereby inhibiting its growth and development. Nitrogen input from nearby farmland may be an important factor caused excessive N/K ratio in both soil and S. palustre in association Ⅳ.