Shuijiang Nature Reserve is located in Yushan Mountains in the middle of Jiangxi Province, is close to the boundary between the north and south of the midsubtropical zone of China, and is rich in byophytes. In this study, more than 700 bryophyte specimens collected from the comprehensive scientific investigation of Shuijiang Nature Reserve in 2019 (used the methods of line transect and quadrat) were identified and statistically analyzed, with related literature consulted to analyze the floristic geographical characteristics of bryophyte groups in the study area, and compared with the adjacent 12 nature reserves. The results show that: (1) a total of 197 bryophytes belonging to 57 families and 102 genera were collected and identified during the investigation. (2) There are 10 species of bryophyte floristic components in Shuijiang Nature Reserve, the main constituents are East Asian, Tropical Asia and North Temperate, accounting for 35.91%, 19.89% and 17.68% of the total species, respectively, and the endemic distribution in China accounts for 12.71%. (3) Compared with 12 nature reserve in South China, the similarity coefficient between Shuijiang and Taohonglin is the highest, reaching 0.44; Cluster analysis and principal component analysis based on the genealogy of floristic components show that Shuijiang is closely related to Northwest Hunan, Tongbo Mountains and Leigong Mountains. (4) The distribution of most species of mosses endemic to China in the Shuijiang reserve conforms to the theory of origin and spread from the Himalayas and adjacent areas; whereas other species are distributed and spread in the vicinity, which is related to the preservation of numerous plant groups in the mountains of eastern China as glacial refugia.