To understand the plant community species diversity characteristics at different succession stages in Baili Rhododendron Nature Reserve of Guizhou, we investigated the community of five succession stages in the protected area with the research method of “space instead of time”, analyzed species composition, important values, α and β diversity characteristics. The results were as follows: (1) a total of 140 species of vascular plants were investigated, belonging to 56 families and 103 genera. The dominant families were Rosaceae, Rhododendron, and Liliaceae. (2) Rhododendrons occupy a comprehensive dominant position in the whole succession process, and the important values of the shrub layer rank top three in each succession stage. (3) Along the direction of succession, community Margalef abundance index (d_Ma), ShannonWiener diversity index (H′_e), Simpson index (D) and the Pielou evenness index (J_e) follow down after rising first and then an upward trend, finally community structure tended to be complex, the stability of rising. (4) With the succession going forward, the number of species lost and increased between communities gradually increased, and the species substitution rate gradually increased. The similarity coefficient of species in the whole succession process is expressed as extremely dissimilar between different adjacent stages. The study believes that in the future protection process, protected areas should develop reasonable protection measures to avoid the destruction of human activities, improve community stability, protect community structure and species diversity, and provide scientific support for ecological functions and sustainable development.