Based on field investigations, collecting literature, and collating plant databases, we analyzed the flora composition and distribution types of Firminana danxiaens Nature Reserve in Guangdong Province, and the similarities between three neighboring study areas. The results showed that: (1) there were 84 species of pteridophytes belonging to 51 genera and 28 families in Nanxiong Firminana danxiaens Nature Reserve, with a single family structure and a low level of differentiation. Most of them belonged to oligo families, but the origin of the flora was ancient and the evolutionary relationship was coherent. (2) The fern flora in this area was widely geographically related, and had a high degree of kinship with the tropics at the family and genus levels. It was mainly distributed in the pantropical and subtropical regions, and at the species level in terms of tropical Asia and East Asia. Mainly, it had a permeable transition from tropical to temperate zones. (3) Geographically, the fern flora of Firminana danxiaens Nature Reserve was closely related to the fern flora of Guanyindong, followed by Guanzhai Mountain, and distanced from Danxia Mountain. The similarity coefficient between this Firminana danxiaens Nature Reserue and Guanyindong was above 0.83, and the floristic homogeneity was obvious, which consistent with the fact that the modern natural conditions of the two were similar. The results provide an important basis for discussing the origin and development of ferns in Danxia landform, and have reference significance for the rational development and utilization of plant resources in Firminana danxiaens Nature Reserve in Guangdong Province.