[Objective] Differences of plant species composition, community structure, and diversity in different soil erosion control years in the granite erosion area were compared and analyzed in order to provide a scientific basis for soil erosion control and ecological reconstruction in the granite erosion area. [Methods] The method of replacing time with space was adopted. In the Pingjiang River basin of Xingguo County, Jiangxi Province, four artificial forests with different treatment years of 4, 14, 24, and 34 years were selected as the research objects, and the untreated forest and secondary forest were taken as the control. The species composition, community structure, and plant diversity of plant communities in different areas were investigated and analyzed by the quadrat survey method. [Results] ① 43 species of plants were investigated, belonging to 31 families and 41 genera, including 17 species in the arbor layer, eight species in the shrub layer, and 18 species in the herb layer. ② The “bamboo ditch + arbor, shrub and grass” measures could effectively increase plant diversity and promote vegetation restoration and succession. The Simpson index and Shannon-Wiener index of forest lands with different management years were greater than those of forest lands without artificial management. ③ With the increase of water and soil loss control years, the Simpson, Shannon-Wiener, and evenness indexes of the plant community showed upward-decreasing-increasing trends, and they were all smaller than secondary forests. ④ There were fewer common species in the woodland of different treatment years, secondary forest, and untreated forest, which showed dissimilarity on the whole. [Conclusion] It is difficult to effectively restore plant diversity in granite erosion areas only by natural closure. The “bamboo ditch + arbor, shrub and grass” measures could effectively promote vegetation restoration and increase plant diversity.